256515642 has 24 divisors (see below), whose sum is σ = 579949344. Its totient is φ = 81787464.

The previous prime is 256515641. The next prime is 256515653. The reversal of 256515642 is 246515652.

256515642 is a `hidden beast` number, since 2 + 5 + 6 + 5 + 1 + 5 + 642 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 256515597 and 256515606.

It is not an unprimeable number, because it can be changed into a prime (256515641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 309388 + ... + 310215.

It is an arithmetic number, because the mean of its divisors is an integer number (24164556).

Almost surely, 2^256515642 is an apocalyptic number.

256515642 is an abundant number, since it is smaller than the sum of its proper divisors (323433702).

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

256515642 is a wasteful number, since it uses less digits than its factorization.

256515642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 619634 (or 619631 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The square root of 256515642 is about 16016.1057064444. The cubic root of 256515642 is about 635.3864529220.

The spelling of 256515642 in words is "two hundred fifty-six million, five hundred fifteen thousand, six hundred forty-two".