21626131 has 2 divisors, whose sum is σ = 21626132. Its totient is φ = 21626130.

The previous prime is 21626051. The next prime is 21626149. The reversal of 21626131 is 13162612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21626131 is a prime.

It is a super-2 number, since 2×21626131² = 935379084058322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21623131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10813065 + 10813066.

It is an arithmetic number, because the mean of its divisors is an integer number (10813066).

Almost surely, 2^21626131 is an apocalyptic number.

21626131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21626131 is an equidigital number, since it uses as much as digits as its factorization.

21626131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 22.

The square root of 21626131 is about 4650.3904137180. The cubic root of 21626131 is about 278.6075897204.

Adding to 21626131 its reverse (13162612), we get a palindrome (34788743).

The spelling of 21626131 in words is "twenty-one million, six hundred twenty-six thousand, one hundred thirty-one".