21900979031 has 2 divisors, whose sum is σ = 21900979032. Its totient is φ = 21900979030.

The previous prime is 21900979013. The next prime is 21900979043. The reversal of 21900979031 is 13097900912.

Together with previous prime (21900979013) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21900979031 - 2¹⁴ = 21900962647 is a prime.

It is a super-2 number, since 2×21900979031² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21900979031.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21900979081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10950489515 + 10950489516.

It is an arithmetic number, because the mean of its divisors is an integer number (10950489516).

Almost surely, 2^21900979031 is an apocalyptic number.

21900979031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21900979031 is an equidigital number, since it uses as much as digits as its factorization.

21900979031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30618, while the sum is 41.

The spelling of 21900979031 in words is "twenty-one billion, nine hundred million, nine hundred seventy-nine thousand, thirty-one".