21431613664 has 24 divisors (see below), whose sum is σ = 42204282120. Its totient is φ = 10713065856.

The previous prime is 21431613661. The next prime is 21431613667. The reversal of 21431613664 is 46631613412.

It is an interprime number because it is at equal distance from previous prime (21431613661) and next prime (21431613667).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431613661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44442 + ... + 211750.

It is an arithmetic number, because the mean of its divisors is an integer number (1758511755).

Almost surely, 2^21431613664 is an apocalyptic number.

It is an amenable number.

21431613664 is a deficient number, since it is larger than the sum of its proper divisors (20772668456).

21431613664 is a wasteful number, since it uses less digits than its factorization.

21431613664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171322 (or 171314 counting only the distinct ones).

The product of its digits is 62208, while the sum is 37.

The spelling of 21431613664 in words is "twenty-one billion, four hundred thirty-one million, six hundred thirteen thousand, six hundred sixty-four".