51257916 has 36 divisors (see below), whose sum is σ = 129808224. Its totient is φ = 17054400.

The previous prime is 51257909. The next prime is 51257917. The reversal of 51257916 is 61975215.

51257916 is a `hidden beast` number, since 512 + 57 + 91 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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 (51257917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26461 + ... + 28331.

It is an arithmetic number, because the mean of its divisors is an integer number (3605784).

Almost surely, 2^51257916 is an apocalyptic number.

It is an amenable number.

51257916 is an abundant number, since it is smaller than the sum of its proper divisors (78550308).

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

51257916 is a wasteful number, since it uses less digits than its factorization.

51257916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2642 (or 2637 counting only the distinct ones).

The product of its digits is 18900, while the sum is 36.

The square root of 51257916 is about 7159.4633877128. The cubic root of 51257916 is about 371.4670655230.

It can be divided in two parts, 5125 and 7916, that added together give a triangular number (13041 = T₁₆₁).

The spelling of 51257916 in words is "fifty-one million, two hundred fifty-seven thousand, nine hundred sixteen".