51865720 has 32 divisors (see below), whose sum is σ = 118681200. Its totient is φ = 20393728.

The previous prime is 51865711. The next prime is 51865721. The reversal of 51865720 is 2756815.

51865720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×51865720² = 5380105822236800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51865721) 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 7 ways as a sum of consecutive naturals, for example, 8629 + ... + 13348.

Almost surely, 2^51865720 is an apocalyptic number.

It is an amenable number.

51865720 is an abundant number, since it is smaller than the sum of its proper divisors (66815480).

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

51865720 is a wasteful number, since it uses less digits than its factorization.

51865720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22047 (or 22043 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 34.

The square root of 51865720 is about 7201.7858896249. The cubic root of 51865720 is about 372.9295556580.

The spelling of 51865720 in words is "fifty-one million, eight hundred sixty-five thousand, seven hundred twenty".