21266331431 has 2 divisors, whose sum is σ = 21266331432. Its totient is φ = 21266331430.

The previous prime is 21266331389. The next prime is 21266331469. The reversal of 21266331431 is 13413366212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21266331431 - 2¹⁴ = 21266315047 is a prime.

It is a super-2 number, since 2×21266331431² (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 (21266331491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10633165715 + 10633165716.

It is an arithmetic number, because the mean of its divisors is an integer number (10633165716).

Almost surely, 2^21266331431 is an apocalyptic number.

21266331431 is a deficient number, since it is larger than the sum of its proper divisors (1).

21266331431 is an equidigital number, since it uses as much as digits as its factorization.

21266331431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 32.

Adding to 21266331431 its reverse (13413366212), we get a palindrome (34679697643).

The spelling of 21266331431 in words is "twenty-one billion, two hundred sixty-six million, three hundred thirty-one thousand, four hundred thirty-one".