21651342631 has 8 divisors (see below), whose sum is σ = 23177174400. Its totient is φ = 20164139640.

The previous prime is 21651342599. The next prime is 21651342641. The reversal of 21651342631 is 13624315612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21651342631 - 2⁵ = 21651342599 is a prime.

It is a super-2 number, since 2×21651342631² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21651342641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9656035 + ... + 9658276.

It is an arithmetic number, because the mean of its divisors is an integer number (2897146800).

Almost surely, 2^21651342631 is an apocalyptic number.

21651342631 is a deficient number, since it is larger than the sum of its proper divisors (1525831769).

21651342631 is a wasteful number, since it uses less digits than its factorization.

21651342631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19314389.

The product of its digits is 25920, while the sum is 34.

The spelling of 21651342631 in words is "twenty-one billion, six hundred fifty-one million, three hundred forty-two thousand, six hundred thirty-one".