256491510 has 32 divisors (see below), whose sum is σ = 671542272. Its totient is φ = 62179680.

The previous prime is 256491493. The next prime is 256491541. The reversal of 256491510 is 15194652.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 388294 + ... + 388953.

It is an arithmetic number, because the mean of its divisors is an integer number (20985696).

Almost surely, 2^256491510 is an apocalyptic number.

256491510 is an abundant number, since it is smaller than the sum of its proper divisors (415050762).

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

256491510 is a wasteful number, since it uses less digits than its factorization.

256491510 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777268.

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 256491510 is about 16015.3523220690. The cubic root of 256491510 is about 635.3665273967.

The spelling of 256491510 in words is "two hundred fifty-six million, four hundred ninety-one thousand, five hundred ten".