256399392 has 96 divisors (see below), whose sum is σ = 688564800. Its totient is φ = 83524608.

The previous prime is 256399387. The next prime is 256399447. The reversal of 256399392 is 293993652.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1119534 + ... + 1119762.

It is an arithmetic number, because the mean of its divisors is an integer number (7172550).

Almost surely, 2^256399392 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 256399392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (344282400).

256399392 is an abundant number, since it is smaller than the sum of its proper divisors (432165408).

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

256399392 is a wasteful number, since it uses less digits than its factorization.

256399392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458 (or 450 counting only the distinct ones).

The product of its digits is 787320, while the sum is 48.

The square root of 256399392 is about 16012.4761358136. The cubic root of 256399392 is about 635.2904550906.

The spelling of 256399392 in words is "two hundred fifty-six million, three hundred ninety-nine thousand, three hundred ninety-two".