51865812 has 48 divisors (see below), whose sum is σ = 134863680. Its totient is φ = 17237664.

The previous prime is 51865739. The next prime is 51865813. The reversal of 51865812 is 21856815.

51865812 is a `hidden beast` number, since 518 + 65 + 81 + 2 = 666.

51865812 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51865813) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 60378 + ... + 61230.

It is an arithmetic number, because the mean of its divisors is an integer number (2809660).

Almost surely, 2^51865812 is an apocalyptic number.

It is an amenable number.

51865812 is an abundant number, since it is smaller than the sum of its proper divisors (82997868).

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

51865812 is a wasteful number, since it uses less digits than its factorization.

51865812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1429 (or 1421 counting only the distinct ones).

The product of its digits is 19200, while the sum is 36.

The square root of 51865812 is about 7201.7922769266. The cubic root of 51865812 is about 372.9297761601.

The spelling of 51865812 in words is "fifty-one million, eight hundred sixty-five thousand, eight hundred twelve".