256439947200 has 336 divisors, whose sum is σ = 874573368960. Its totient is φ = 65705472000.

The previous prime is 256439947193. The next prime is 256439947271. The reversal of 256439947200 is 2749934652.

It is a Cunningham number, because it is equal to 506399²-1.

It is a super-2 number, since 2×256439947200² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 29366835 + ... + 29375565.

Almost surely, 2^256439947200 is an apocalyptic number.

256439947200 is a gapful number since it is divisible by the number (20) 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 256439947200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (437286684480).

256439947200 is an abundant number, since it is smaller than the sum of its proper divisors (618133421760).

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

256439947200 is a wasteful number, since it uses less digits than its factorization.

256439947200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8996 (or 8981 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 51.

The spelling of 256439947200 in words is "two hundred fifty-six billion, four hundred thirty-nine million, nine hundred forty-seven thousand, two hundred".