21163131612664 has 32 divisors (see below), whose sum is σ = 40754211393600. Its totient is φ = 10295354309760.

The previous prime is 21163131612577. The next prime is 21163131612683. The reversal of 21163131612664 is 46621613136112.

It is a self number, because there is not a number n which added to its sum of digits gives 21163131612664.

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, 13332657 + ... + 14835295.

It is an arithmetic number, because the mean of its divisors is an integer number (1273569106050).

Almost surely, 2^{21163131612664} is an apocalyptic number.

It is an amenable number.

21163131612664 is a deficient number, since it is larger than the sum of its proper divisors (19591079780936).

21163131612664 is a wasteful number, since it uses less digits than its factorization.

21163131612664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1550263 (or 1550259 counting only the distinct ones).

The product of its digits is 186624, while the sum is 43.

Adding to 21163131612664 its reverse (46621613136112), we get a palindrome (67784744748776).

The spelling of 21163131612664 in words is "twenty-one trillion, one hundred sixty-three billion, one hundred thirty-one million, six hundred twelve thousand, six hundred sixty-four".