256787349820 has 12 divisors (see below), whose sum is σ = 539253434664. Its totient is φ = 102714939920.

The previous prime is 256787349703. The next prime is 256787349821. The reversal of 256787349820 is 28943787652.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256787349821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6419683726 + ... + 6419683765.

It is an arithmetic number, because the mean of its divisors is an integer number (44937786222).

Almost surely, 2^256787349820 is an apocalyptic number.

256787349820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256787349820 is an abundant number, since it is smaller than the sum of its proper divisors (282466084844).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256787349820 is a wasteful number, since it uses less digits than its factorization.

256787349820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12839367500 (or 12839367498 counting only the distinct ones).

The product of its (nonzero) digits is 40642560, while the sum is 61.

The spelling of 256787349820 in words is "two hundred fifty-six billion, seven hundred eighty-seven million, three hundred forty-nine thousand, eight hundred twenty".