51697992386 has 4 divisors (see below), whose sum is σ = 77546988582. Its totient is φ = 25848996192.

The previous prime is 51697992317. The next prime is 51697992403. The reversal of 51697992386 is 68329979615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68329979615 = 5 ⋅13665995923.

It can be written as a sum of positive squares in only one way, i.e., 41381730625 + 10316261761 = 203425^2 + 101569^2 .

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 12924498095 + ... + 12924498098.

Almost surely, 2^51697992386 is an apocalyptic number.

51697992386 is a deficient number, since it is larger than the sum of its proper divisors (25848996196).

51697992386 is a wasteful number, since it uses less digits than its factorization.

51697992386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25848996195.

The product of its digits is 44089920, while the sum is 65.

The spelling of 51697992386 in words is "fifty-one billion, six hundred ninety-seven million, nine hundred ninety-two thousand, three hundred eighty-six".