51821865683 has 16 divisors (see below), whose sum is σ = 60059091456. Its totient is φ = 43793628480.

The previous prime is 51821865677. The next prime is 51821865707. The reversal of 51821865683 is 38656812815.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-51821865683 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51821865673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1434938 + ... + 1470608.

It is an arithmetic number, because the mean of its divisors is an integer number (3753693216).

Almost surely, 2^51821865683 is an apocalyptic number.

51821865683 is a deficient number, since it is larger than the sum of its proper divisors (8237225773).

51821865683 is a wasteful number, since it uses less digits than its factorization.

51821865683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38594.

The product of its digits is 2764800, while the sum is 53.

The spelling of 51821865683 in words is "fifty-one billion, eight hundred twenty-one million, eight hundred sixty-five thousand, six hundred eighty-three".