256356904489 has 15 divisors (see below), whose sum is σ = 299094205623. Its totient is φ = 219713224248.

The previous prime is 256356904469. The next prime is 256356904493. The reversal of 256356904489 is 984409653652.

The square root of 256356904489 is 506317.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 189116265625 + 67240638864 = 434875^2 + 259308^2 .

It is not a de Polignac number, because 256356904489 - 2⁷ = 256356904361 is a prime.

It is a super-2 number, since 2×256356904489² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256356904439) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 24804367 + ... + 24814699.

Almost surely, 2^256356904489 is an apocalyptic number.

256356904489 is the 506317-th square number.

256356904489 is the 253159-th centered octagonal number.

It is an amenable number.

256356904489 is a deficient number, since it is larger than the sum of its proper divisors (42737301134).

256356904489 is an frugal number, since it uses more digits than its factorization.

256356904489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20694 (or 10340 counting only the distinct ones).

The product of its (nonzero) digits is 55987200, while the sum is 61.

The spelling of 256356904489 in words is "two hundred fifty-six billion, three hundred fifty-six million, nine hundred four thousand, four hundred eighty-nine".