21269588731 has 2 divisors, whose sum is σ = 21269588732. Its totient is φ = 21269588730.

The previous prime is 21269588723. The next prime is 21269588759. The reversal of 21269588731 is 13788596212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21269588731 - 2³ = 21269588723 is a prime.

It is a super-2 number, since 2×21269588731² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21269588831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10634794365 + 10634794366.

It is an arithmetic number, because the mean of its divisors is an integer number (10634794366).

Almost surely, 2^21269588731 is an apocalyptic number.

21269588731 is a deficient number, since it is larger than the sum of its proper divisors (1).

21269588731 is an equidigital number, since it uses as much as digits as its factorization.

21269588731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1451520, while the sum is 52.

The spelling of 21269588731 in words is "twenty-one billion, two hundred sixty-nine million, five hundred eighty-eight thousand, seven hundred thirty-one".