251651120 has 80 divisors (see below), whose sum is σ = 670695168. Its totient is φ = 86019840.

The previous prime is 251651111. The next prime is 251651123. The reversal of 251651120 is 21156152.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (251651123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 319367 + ... + 320153.

Almost surely, 2^251651120 is an apocalyptic number.

251651120 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 251651120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (335347584).

251651120 is an abundant number, since it is smaller than the sum of its proper divisors (419044048).

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

251651120 is a wasteful number, since it uses less digits than its factorization.

251651120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1378 (or 1372 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 251651120 is about 15863.5153733339. The cubic root of 251651120 is about 631.3443368472.

The spelling of 251651120 in words is "two hundred fifty-one million, six hundred fifty-one thousand, one hundred twenty".