251138648 has 8 divisors (see below), whose sum is σ = 470884980. Its totient is φ = 125569320.

The previous prime is 251138623. The next prime is 251138683. The reversal of 251138648 is 846831152.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15696158 + ... + 15696173.

Almost surely, 2^251138648 is an apocalyptic number.

It is an amenable number.

251138648 is a deficient number, since it is larger than the sum of its proper divisors (219746332).

251138648 is a wasteful number, since it uses less digits than its factorization.

251138648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31392337 (or 31392333 counting only the distinct ones).

The product of its digits is 46080, while the sum is 38.

The square root of 251138648 is about 15847.3546057378. The cubic root of 251138648 is about 630.9154809889.

The spelling of 251138648 in words is "two hundred fifty-one million, one hundred thirty-eight thousand, six hundred forty-eight".