256720518 has 12 divisors (see below), whose sum is σ = 556227828. Its totient is φ = 85573500.

The previous prime is 256720511. The next prime is 256720531. The reversal of 256720518 is 815027652.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256720511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7131108 + ... + 7131143.

It is an arithmetic number, because the mean of its divisors is an integer number (46352319).

Almost surely, 2^256720518 is an apocalyptic number.

256720518 is an abundant number, since it is smaller than the sum of its proper divisors (299507310).

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

256720518 is a wasteful number, since it uses less digits than its factorization.

256720518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14262259 (or 14262256 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 256720518 is about 16022.5003666719. The cubic root of 256720518 is about 635.5555664476. Note that the first 4 decimals are identical.

The spelling of 256720518 in words is "two hundred fifty-six million, seven hundred twenty thousand, five hundred eighteen".