51972768 has 72 divisors (see below), whose sum is σ = 149198868. Its totient is φ = 17160192.

The previous prime is 51972763. The next prime is 51972769. The reversal of 51972768 is 86727915.

51972768 is a `hidden beast` number, since 519 + 72 + 7 + 68 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 40602384 + 11370384 = 6372^2 + 3372^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×51972768² = 5402337227163648, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51972763) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31746 + ... + 33342.

Almost surely, 2^51972768 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 51972768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74599434).

51972768 is an abundant number, since it is smaller than the sum of its proper divisors (97226100).

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

51972768 is a wasteful number, since it uses less digits than its factorization.

51972768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1726 (or 1715 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 51972768 is about 7209.2141041864. The cubic root of 51972768 is about 373.1859480584.

The spelling of 51972768 in words is "fifty-one million, nine hundred seventy-two thousand, seven hundred sixty-eight".