251057664 has 320 divisors, whose sum is σ = 879943680. Its totient is φ = 69672960.

The previous prime is 251057663. The next prime is 251057671. The reversal of 251057664 is 466750152.

It is a happy number.

251057664 is a `hidden beast` number, since 25 + 1 + 0 + 576 + 64 = 666.

251057664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251057663) 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, 1976769 + ... + 1976895.

It is an arithmetic number, because the mean of its divisors is an integer number (2749824).

Almost surely, 2^251057664 is an apocalyptic number.

251057664 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 251057664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (439971840).

251057664 is an abundant number, since it is smaller than the sum of its proper divisors (628886016).

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

251057664 is a wasteful number, since it uses less digits than its factorization.

251057664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 156 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 251057664 is about 15844.7992729476. The cubic root of 251057664 is about 630.8476571623.

The spelling of 251057664 in words is "two hundred fifty-one million, fifty-seven thousand, six hundred sixty-four".