51387920968 has 8 divisors (see below), whose sum is σ = 96352351830. Its totient is φ = 25693960480.

The previous prime is 51387920951. The next prime is 51387920981. The reversal of 51387920968 is 86902978315.

It can be written as a sum of positive squares in only one way, i.e., 26888784484 + 24499136484 = 163978^2 + 156522^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3211745053 + ... + 3211745068.

Almost surely, 2^51387920968 is an apocalyptic number.

It is an amenable number.

51387920968 is a deficient number, since it is larger than the sum of its proper divisors (44964430862).

51387920968 is a wasteful number, since it uses less digits than its factorization.

51387920968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6423490127 (or 6423490123 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 58.

The spelling of 51387920968 in words is "fifty-one billion, three hundred eighty-seven million, nine hundred twenty thousand, nine hundred sixty-eight".