3643640 has 144 divisors (see below), whose sum is σ = 11265480. Its totient is φ = 1048320.

The previous prime is 3643639. The next prime is 3643657. The reversal of 3643640 is 463463.

3643640 = T₂₁₁ + T₂₁₂ + ... + T₃₁₄.

It is a super-2 number, since 2×3643640² = 26552224899200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 280274 + ... + 280286.

Almost surely, 2^3643640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3643640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5632740).

3643640 is an abundant number, since it is smaller than the sum of its proper divisors (7621840).

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

3643640 is a wasteful number, since it uses less digits than its factorization.

3643640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 26.

The square root of 3643640 is about 1908.8321036697. The cubic root of 3643640 is about 153.8786923484.

It can be divided in two parts, 364 and 3640, that added together give a palindrome (4004).

The spelling of 3643640 in words is "three million, six hundred forty-three thousand, six hundred forty".