251428866 has 32 divisors (see below), whose sum is σ = 544141248. Its totient is φ = 76991040.

The previous prime is 251428841. The next prime is 251428937. The reversal of 251428866 is 668824152.

It is a super-3 number, since 3×251428866³ (a number of 26 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8820 + ... + 24096.

It is an arithmetic number, because the mean of its divisors is an integer number (17004414).

Almost surely, 2^251428866 is an apocalyptic number.

251428866 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

251428866 is an abundant number, since it is smaller than the sum of its proper divisors (292712382).

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

251428866 is a wasteful number, since it uses less digits than its factorization.

251428866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15506.

The product of its digits is 184320, while the sum is 42.

The square root of 251428866 is about 15856.5086321044. The cubic root of 251428866 is about 631.1584179003.

The spelling of 251428866 in words is "two hundred fifty-one million, four hundred twenty-eight thousand, eight hundred sixty-six".