256727662489 has 3 divisors (see below), whose sum is σ = 256728169173. Its totient is φ = 256727155806.

The previous prime is 256727662487. The next prime is 256727662559. The reversal of 256727662489 is 984266727652.

It is a happy number.

The square root of 256727662489 is 506683.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 256727662489 - 2¹ = 256727662487 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256727662489.

It is not an unprimeable number, because it can be changed into a prime (256727662487) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 253342 + ... + 760024.

It is an arithmetic number, because the mean of its divisors is an integer number (85576056391).

Almost surely, 2^256727662489 is an apocalyptic number.

256727662489 is the 506683-rd square number.

256727662489 is the 253342-nd centered octagonal number.

It is an amenable number.

256727662489 is a deficient number, since it is larger than the sum of its proper divisors (506684).

256727662489 is an frugal number, since it uses more digits than its factorization.

256727662489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1013366 (or 506683 counting only the distinct ones).

The product of its digits is 121927680, while the sum is 64.

Multiplying 256727662489 by its sum of digits (64), we get a square (16430570399296 = 4053464²).

The spelling of 256727662489 in words is "two hundred fifty-six billion, seven hundred twenty-seven million, six hundred sixty-two thousand, four hundred eighty-nine".