256421072 has 10 divisors (see below), whose sum is σ = 496815858. Its totient is φ = 128210528.

The previous prime is 256421029. The next prime is 256421101. The reversal of 256421072 is 270124652.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 146506816 + 109914256 = 12104^2 + 10484^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8013143 + ... + 8013174.

Almost surely, 2^256421072 is an apocalyptic number.

It is an amenable number.

256421072 is a deficient number, since it is larger than the sum of its proper divisors (240394786).

256421072 is a wasteful number, since it uses less digits than its factorization.

256421072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16026325 (or 16026319 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 256421072 is about 16013.1530936290. The cubic root of 256421072 is about 635.3083603709.

The spelling of 256421072 in words is "two hundred fifty-six million, four hundred twenty-one thousand, seventy-two".