21211222213931 has 2 divisors, whose sum is σ = 21211222213932. Its totient is φ = 21211222213930.

The previous prime is 21211222213927. The next prime is 21211222213969. The reversal of 21211222213931 is 13931222211212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21211222213931 - 2² = 21211222213927 is a prime.

It is a super-2 number, since 2×21211222213931² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21211222213901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605611106965 + 10605611106966.

It is an arithmetic number, because the mean of its divisors is an integer number (10605611106966).

Almost surely, 2^{21211222213931} is an apocalyptic number.

21211222213931 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211222213931 is an equidigital number, since it uses as much as digits as its factorization.

21211222213931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 32.

The spelling of 21211222213931 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-two million, two hundred thirteen thousand, nine hundred thirty-one".