21116100660 has 24 divisors (see below), whose sum is σ = 59125082016. Its totient is φ = 5630960160.

The previous prime is 21116100617. The next prime is 21116100671. The reversal of 21116100660 is 6600161112.

It is a self number, because there is not a number n which added to its sum of digits gives 21116100660.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175967446 + ... + 175967565.

It is an arithmetic number, because the mean of its divisors is an integer number (2463545084).

Almost surely, 2^21116100660 is an apocalyptic number.

21116100660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21116100660 is an abundant number, since it is smaller than the sum of its proper divisors (38008981356).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21116100660 is a wasteful number, since it uses less digits than its factorization.

21116100660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351935023 (or 351935021 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

Adding to 21116100660 its reverse (6600161112), we get a palindrome (27716261772).

The spelling of 21116100660 in words is "twenty-one billion, one hundred sixteen million, one hundred thousand, six hundred sixty".