256501447749 has 24 divisors (see below), whose sum is σ = 371326010432. Its totient is φ = 170620992000.

The previous prime is 256501447729. The next prime is 256501447759. The reversal of 256501447749 is 947744105652.

256501447749 is a `hidden beast` number, since 2 + 56 + 501 + 4 + 47 + 7 + 49 = 666.

It is not a de Polignac number, because 256501447749 - 2¹⁷ = 256501316677 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 256501447695 and 256501447704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256501447729) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11678472 + ... + 11700414.

Almost surely, 2^256501447749 is an apocalyptic number.

It is an amenable number.

256501447749 is a deficient number, since it is larger than the sum of its proper divisors (114824562683).

256501447749 is a wasteful number, since it uses less digits than its factorization.

256501447749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24777 (or 24774 counting only the distinct ones).

The product of its (nonzero) digits is 8467200, while the sum is 54.

The spelling of 256501447749 in words is "two hundred fifty-six billion, five hundred one million, four hundred forty-seven thousand, seven hundred forty-nine".