21905983031 has 2 divisors, whose sum is σ = 21905983032. Its totient is φ = 21905983030.

The previous prime is 21905983027. The next prime is 21905983039. The reversal of 21905983031 is 13038950912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21905983031 - 2² = 21905983027 is a prime.

It is a super-2 number, since 2×21905983031² (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 21905983031.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21905983039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10952991515 + 10952991516.

It is an arithmetic number, because the mean of its divisors is an integer number (10952991516).

Almost surely, 2^21905983031 is an apocalyptic number.

21905983031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21905983031 is an equidigital number, since it uses as much as digits as its factorization.

21905983031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58320, while the sum is 41.

The spelling of 21905983031 in words is "twenty-one billion, nine hundred five million, nine hundred eighty-three thousand, thirty-one".