21228612631 has 2 divisors, whose sum is σ = 21228612632. Its totient is φ = 21228612630.

The previous prime is 21228612617. The next prime is 21228612673. The reversal of 21228612631 is 13621682212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21228612631 is a prime.

It is a super-2 number, since 2×21228612631² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21228612131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10614306315 + 10614306316.

It is an arithmetic number, because the mean of its divisors is an integer number (10614306316).

Almost surely, 2^21228612631 is an apocalyptic number.

21228612631 is a deficient number, since it is larger than the sum of its proper divisors (1).

21228612631 is an equidigital number, since it uses as much as digits as its factorization.

21228612631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 34.

The spelling of 21228612631 in words is "twenty-one billion, two hundred twenty-eight million, six hundred twelve thousand, six hundred thirty-one".