390656 has 40 divisors (see below), whose sum is σ = 900240. Its totient is φ = 165888.

The previous prime is 390653. The next prime is 390671. The reversal of 390656 is 656093.

It is a super-2 number, since 2×390656² = 305224220672, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3530 + ... + 3638.

It is an arithmetic number, because the mean of its divisors is an integer number (22506).

2³⁹⁰⁶⁵⁶ 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 390656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (450120).

390656 is an abundant number, since it is smaller than the sum of its proper divisors (509584).

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

390656 is an equidigital number, since it uses as much as digits as its factorization.

390656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 29.

The square root of 390656 is about 625.0247995080. The cubic root of 390656 is about 73.1023771546.

The spelling of 390656 in words is "three hundred ninety thousand, six hundred fifty-six".