21377318121 has 8 divisors (see below), whose sum is σ = 31670100960. Its totient is φ = 14251545396.

The previous prime is 21377318111. The next prime is 21377318141. The reversal of 21377318121 is 12181377312.

It is a happy number.

21377318121 is a `hidden beast` number, since 213 + 7 + 7 + 318 + 121 = 666.

It is not a de Polignac number, because 21377318121 - 2⁹ = 21377317609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21377318101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 395876235 + ... + 395876288.

It is an arithmetic number, because the mean of its divisors is an integer number (3958762620).

Almost surely, 2^21377318121 is an apocalyptic number.

It is an amenable number.

21377318121 is a deficient number, since it is larger than the sum of its proper divisors (10292782839).

21377318121 is an equidigital number, since it uses as much as digits as its factorization.

21377318121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791752532 (or 791752526 counting only the distinct ones).

The product of its digits is 14112, while the sum is 36.

The spelling of 21377318121 in words is "twenty-one billion, three hundred seventy-seven million, three hundred eighteen thousand, one hundred twenty-one".