51991992 has 48 divisors (see below), whose sum is σ = 151646040. Its totient is φ = 15997248.

The previous prime is 51991969. The next prime is 51991997. The reversal of 51991992 is 29919915.

51991992 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-3 number, since 3×51991992³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51991997) 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 11 ways as a sum of consecutive naturals, for example, 26838 + ... + 28709.

Almost surely, 2^51991992 is an apocalyptic number.

51991992 is a gapful number since it is divisible by the number (52) formed by its first and last digit.

It is an amenable number.

51991992 is an abundant number, since it is smaller than the sum of its proper divisors (99654048).

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

51991992 is a wasteful number, since it uses less digits than its factorization.

51991992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55572 (or 55565 counting only the distinct ones).

The product of its digits is 65610, while the sum is 45.

The square root of 51991992 is about 7210.5472746526. The cubic root of 51991992 is about 373.2319544741.

The spelling of 51991992 in words is "fifty-one million, nine hundred ninety-one thousand, nine hundred ninety-two".