3689640 has 96 divisors (see below), whose sum is σ = 12359880. Its totient is φ = 953856.

The previous prime is 3689633. The next prime is 3689669. The reversal of 3689640 is 469863.

3689640 is a `hidden beast` number, since 3 + 6 + 8 + 9 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3090564 + 599076 = 1758^2 + 774^2 .

It is a super-2 number, since 2×3689640² = 27226886659200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a junction number, because it is equal to n+sod(n) for n = 3689595 and 3689604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13182 + ... + 13458.

Almost surely, 2^3689640 is an apocalyptic number.

3689640 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 3689640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6179940).

3689640 is an abundant number, since it is smaller than the sum of its proper divisors (8670240).

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

3689640 is a wasteful number, since it uses less digits than its factorization.

3689640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331 (or 324 counting only the distinct ones).

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

The square root of 3689640 is about 1920.8435646871. The cubic root of 3689640 is about 154.5235455993.

It can be divided in two parts, 36 and 89640, that added together give a triangular number (89676 = T₄₂₃).

The spelling of 3689640 in words is "three million, six hundred eighty-nine thousand, six hundred forty".