251640470 has 16 divisors (see below), whose sum is σ = 472646880. Its totient is φ = 96279744.

The previous prime is 251640421. The next prime is 251640497. The reversal of 251640470 is 74046152.

It is a super-2 number, since 2×251640470² = 126645852283641800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 546815 + ... + 547274.

It is an arithmetic number, because the mean of its divisors is an integer number (29540430).

Almost surely, 2^251640470 is an apocalyptic number.

251640470 is a deficient number, since it is larger than the sum of its proper divisors (221006410).

251640470 is a wasteful number, since it uses less digits than its factorization.

251640470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1094119.

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

The square root of 251640470 is about 15863.1796938697. The cubic root of 251640470 is about 631.3354304532.

The spelling of 251640470 in words is "two hundred fifty-one million, six hundred forty thousand, four hundred seventy".