251478864 has 160 divisors (see below), whose sum is σ = 888554240. Its totient is φ = 66313728.

The previous prime is 251478863. The next prime is 251478893. The reversal of 251478864 is 468874152.

251478864 is a `hidden beast` number, since 2 + 514 + 78 + 8 + 64 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251478863) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36114 + ... + 42510.

It is an arithmetic number, because the mean of its divisors is an integer number (5553464).

Almost surely, 2^251478864 is an apocalyptic number.

251478864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251478864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (444277120).

251478864 is an abundant number, since it is smaller than the sum of its proper divisors (637075376).

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

251478864 is a wasteful number, since it uses less digits than its factorization.

251478864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6434 (or 6422 counting only the distinct ones).

The product of its digits is 430080, while the sum is 45.

The square root of 251478864 is about 15858.0851303050. The cubic root of 251478864 is about 631.2002515577.

The spelling of 251478864 in words is "two hundred fifty-one million, four hundred seventy-eight thousand, eight hundred sixty-four".