18640256 has 32 divisors (see below), whose sum is σ = 37509480. Its totient is φ = 9226240.

The previous prime is 18640253. The next prime is 18640261. The reversal of 18640256 is 65204681.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18640253) 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, 13016 + ... + 14376.

Almost surely, 2^18640256 is an apocalyptic number.

18640256 is a gapful number since it is divisible by the number (16) 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 18640256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18754740).

18640256 is an abundant number, since it is smaller than the sum of its proper divisors (18869224).

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

18640256 is a wasteful number, since it uses less digits than its factorization.

18640256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1482 (or 1470 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 18640256 is about 4317.4362763103. The cubic root of 18640256 is about 265.1453148660.

The spelling of 18640256 in words is "eighteen million, six hundred forty thousand, two hundred fifty-six".