251099980 has 24 divisors (see below), whose sum is σ = 545494320. Its totient is φ = 96976320.

The previous prime is 251099963. The next prime is 251100001. The reversal of 251099980 is 89990152.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 215886 + ... + 217045.

It is an arithmetic number, because the mean of its divisors is an integer number (22728930).

Almost surely, 2^251099980 is an apocalyptic number.

251099980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251099980 is an abundant number, since it is smaller than the sum of its proper divisors (294394340).

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

251099980 is a wasteful number, since it uses less digits than its factorization.

251099980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432969 (or 432967 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 43.

The square root of 251099980 is about 15846.1345444244. The cubic root of 251099980 is about 630.8830984886.

The spelling of 251099980 in words is "two hundred fifty-one million, ninety-nine thousand, nine hundred eighty".