251206560 has 144 divisors (see below), whose sum is σ = 935232480. Its totient is φ = 60894720.

The previous prime is 251206541. The next prime is 251206567. The reversal of 251206560 is 65602152.

251206560 is a `hidden beast` number, since 2 + 5 + 1 + 2 + 0 + 656 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is not an unprimeable number, because it can be changed into a prime (251206567) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7911 + ... + 23769.

It is an arithmetic number, because the mean of its divisors is an integer number (6494670).

Almost surely, 2^251206560 is an apocalyptic number.

251206560 is a gapful number since it is divisible by the number (20) 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 251206560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (467616240).

251206560 is an abundant number, since it is smaller than the sum of its proper divisors (684025920).

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

251206560 is a wasteful number, since it uses less digits than its factorization.

251206560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15891 (or 15880 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 251206560 is about 15849.4971529068. The cubic root of 251206560 is about 630.9723458202.

The spelling of 251206560 in words is "two hundred fifty-one million, two hundred six thousand, five hundred sixty".