51870640 has 20 divisors (see below), whose sum is σ = 120599424. Its totient is φ = 20748224.

The previous prime is 51870631. The next prime is 51870659. The reversal of 51870640 is 4607815.

It is a tau number, because it is divible by the number of its divisors (20).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 324112 + ... + 324271.

Almost surely, 2^51870640 is an apocalyptic number.

It is an amenable number.

51870640 is an abundant number, since it is smaller than the sum of its proper divisors (68728784).

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

51870640 is a wasteful number, since it uses less digits than its factorization.

51870640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 648396 (or 648390 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 51870640 is about 7202.1274634652. The cubic root of 51870640 is about 372.9413473603.

The spelling of 51870640 in words is "fifty-one million, eight hundred seventy thousand, six hundred forty".