51681992 has 8 divisors (see below), whose sum is σ = 96903750. Its totient is φ = 25840992.

The previous prime is 51681979. The next prime is 51682027. The reversal of 51681992 is 29918615.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 27730756 + 23951236 = 5266^2 + 4894^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 3230117 + ... + 3230132.

Almost surely, 2^51681992 is an apocalyptic number.

It is an amenable number.

51681992 is a deficient number, since it is larger than the sum of its proper divisors (45221758).

51681992 is a wasteful number, since it uses less digits than its factorization.

51681992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6460255 (or 6460251 counting only the distinct ones).

The product of its digits is 38880, while the sum is 41.

The square root of 51681992 is about 7189.0188482157. The cubic root of 51681992 is about 372.4886821479.

The spelling of 51681992 in words is "fifty-one million, six hundred eighty-one thousand, nine hundred ninety-two".