51685312 has 56 divisors (see below), whose sum is σ = 119985536. Its totient is φ = 21627648.

The previous prime is 51685273. The next prime is 51685313. The reversal of 51685312 is 21358615.

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51685313) 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 7 ways as a sum of consecutive naturals, for example, 17923 + ... + 20605.

Almost surely, 2^51685312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51685312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59992768).

51685312 is an abundant number, since it is smaller than the sum of its proper divisors (68300224).

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

51685312 is a wasteful number, since it uses less digits than its factorization.

51685312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2745 (or 2735 counting only the distinct ones).

The product of its digits is 7200, while the sum is 31.

The square root of 51685312 is about 7189.2497522342. The cubic root of 51685312 is about 372.4966580785.

The spelling of 51685312 in words is "fifty-one million, six hundred eighty-five thousand, three hundred twelve".