3869640 has 64 divisors (see below), whose sum is σ = 12902400. Its totient is φ = 1031616.

The previous prime is 3869639. The next prime is 3869641. The reversal of 3869640 is 469683.

3869640 is a `hidden beast` number, since 3 + 8 + 6 + 9 + 640 = 666.

3869640 is digitally balanced in base 2 and base 5, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (3869639) and next prime (3869641).

It is a super-2 number, since 2×3869640² = 29948227459200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 3869595 and 3869604.

It is not an unprimeable number, because it can be changed into a prime (3869641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 712 + ... + 2871.

It is an arithmetic number, because the mean of its divisors is an integer number (201600).

Almost surely, 2^3869640 is an apocalyptic number.

3869640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3869640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6451200).

3869640 is an abundant number, since it is smaller than the sum of its proper divisors (9032760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3869640 is a wasteful number, since it uses less digits than its factorization.

3869640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3603 (or 3593 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 3869640 is about 1967.1400560204. The cubic root of 3869640 is about 156.9965785561.

The spelling of 3869640 in words is "three million, eight hundred sixty-nine thousand, six hundred forty".