21272945831 has 2 divisors, whose sum is σ = 21272945832. Its totient is φ = 21272945830.

The previous prime is 21272945821. The next prime is 21272945833. The reversal of 21272945831 is 13854927212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21272945831 is a prime.

It is a super-2 number, since 2×21272945831² (a number of 21 digits) contains 22 as substring.

Together with 21272945833, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21272945833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10636472915 + 10636472916.

It is an arithmetic number, because the mean of its divisors is an integer number (10636472916).

Almost surely, 2^21272945831 is an apocalyptic number.

21272945831 is a deficient number, since it is larger than the sum of its proper divisors (1).

21272945831 is an equidigital number, since it uses as much as digits as its factorization.

21272945831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 44.

The spelling of 21272945831 in words is "twenty-one billion, two hundred seventy-two million, nine hundred forty-five thousand, eight hundred thirty-one".