51187665 has 48 divisors (see below), whose sum is σ = 87511104. Its totient is φ = 25534080.

The previous prime is 51187657. The next prime is 51187679. The reversal of 51187665 is 56678115.

51187665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51187665 - 2³ = 51187657 is a prime.

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 in 47 ways as a sum of consecutive naturals, for example, 763962 + ... + 764028.

It is an arithmetic number, because the mean of its divisors is an integer number (1823148).

Almost surely, 2^51187665 is an apocalyptic number.

It is an amenable number.

51187665 is a deficient number, since it is larger than the sum of its proper divisors (36323439).

51187665 is a wasteful number, since it uses less digits than its factorization.

51187665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190 (or 159 counting only the distinct ones).

The product of its digits is 50400, while the sum is 39.

The square root of 51187665 is about 7154.5555417510. Note that the first 4 decimals coincide. The cubic root of 51187665 is about 371.2972845032.

The spelling of 51187665 in words is "fifty-one million, one hundred eighty-seven thousand, six hundred sixty-five".