256686397149 has 96 divisors (see below), whose sum is σ = 436671379200. Its totient is φ = 133990391808.

The previous prime is 256686397147. The next prime is 256686397183. The reversal of 256686397149 is 941793686652.

It is not a de Polignac number, because 256686397149 - 2¹ = 256686397147 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256686397149.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256686397147) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 16860789 + ... + 16876005.

It is an arithmetic number, because the mean of its divisors is an integer number (4548660200).

Almost surely, 2^256686397149 is an apocalyptic number.

It is an amenable number.

256686397149 is a deficient number, since it is larger than the sum of its proper divisors (179984982051).

256686397149 is a wasteful number, since it uses less digits than its factorization.

256686397149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15364 (or 15337 counting only the distinct ones).

The product of its digits is 117573120, while the sum is 66.

The spelling of 256686397149 in words is "two hundred fifty-six billion, six hundred eighty-six million, three hundred ninety-seven thousand, one hundred forty-nine".