256667489777 has 8 divisors (see below), whose sum is σ = 258835676160. Its totient is φ = 254507891040.

The previous prime is 256667489747. The next prime is 256667489821. The reversal of 256667489777 is 777984766652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256667489777 - 2²⁴ = 256650712561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256667489707) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2086877 + ... + 2206442.

It is an arithmetic number, because the mean of its divisors is an integer number (32354459520).

Almost surely, 2^256667489777 is an apocalyptic number.

It is an amenable number.

256667489777 is a deficient number, since it is larger than the sum of its proper divisors (2168186383).

256667489777 is a wasteful number, since it uses less digits than its factorization.

256667489777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4293823.

The product of its digits is 1493614080, while the sum is 74.

The spelling of 256667489777 in words is "two hundred fifty-six billion, six hundred sixty-seven million, four hundred eighty-nine thousand, seven hundred seventy-seven".