51239685 has 16 divisors (see below), whose sum is σ = 93695616. Its totient is φ = 23423808.

The previous prime is 51239677. The next prime is 51239693. The reversal of 51239685 is 58693215.

51239685 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (51239677) and next prime (51239693).

It is not a de Polignac number, because 51239685 - 2³ = 51239677 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 15 ways as a sum of consecutive naturals, for example, 243894 + ... + 244103.

It is an arithmetic number, because the mean of its divisors is an integer number (5855976).

Almost surely, 2^51239685 is an apocalyptic number.

It is an amenable number.

51239685 is a deficient number, since it is larger than the sum of its proper divisors (42455931).

51239685 is a wasteful number, since it uses less digits than its factorization.

51239685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488012.

The product of its digits is 64800, while the sum is 39.

The square root of 51239685 is about 7158.1900645345. The cubic root of 51239685 is about 371.4230201692.

The spelling of 51239685 in words is "fifty-one million, two hundred thirty-nine thousand, six hundred eighty-five".