51972821866 has 32 divisors (see below), whose sum is σ = 91311840000. Its totient is φ = 22176732816.

The previous prime is 51972821837. The next prime is 51972821867. The reversal of 51972821866 is 66812827915.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (51972821867) 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, 8326 + ... + 322513.

It is an arithmetic number, because the mean of its divisors is an integer number (2853495000).

Almost surely, 2^51972821866 is an apocalyptic number.

51972821866 is a deficient number, since it is larger than the sum of its proper divisors (39339018134).

51972821866 is a wasteful number, since it uses less digits than its factorization.

51972821866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331091 (or 331077 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 55.

The spelling of 51972821866 in words is "fifty-one billion, nine hundred seventy-two million, eight hundred twenty-one thousand, eight hundred sixty-six".