251561376 has 288 divisors, whose sum is σ = 861876288. Its totient is φ = 71331840.

The previous prime is 251561371. The next prime is 251561383. The reversal of 251561376 is 673165152.

251561376 is a `hidden beast` number, since 2 + 515 + 6 + 137 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is a self number, because there is not a number n which added to its sum of digits gives 251561376.

It is not an unprimeable number, because it can be changed into a prime (251561371) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1454026 + ... + 1454198.

It is an arithmetic number, because the mean of its divisors is an integer number (2992626).

Almost surely, 2^251561376 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251561376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (430938144).

251561376 is an abundant number, since it is smaller than the sum of its proper divisors (610314912).

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

251561376 is a wasteful number, since it uses less digits than its factorization.

251561376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 206 counting only the distinct ones).

The product of its digits is 37800, while the sum is 36.

The square root of 251561376 is about 15860.6864920785. The cubic root of 251561376 is about 631.2692777696.

The spelling of 251561376 in words is "two hundred fifty-one million, five hundred sixty-one thousand, three hundred seventy-six".