21122031989 has 2 divisors, whose sum is σ = 21122031990. Its totient is φ = 21122031988.

The previous prime is 21122031937. The next prime is 21122032027. The reversal of 21122031989 is 98913022112.

It is an a-pointer prime, because the next prime (21122032027) can be obtained adding 21122031989 to its sum of digits (38).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19727607025 + 1394424964 = 140455^2 + 37342^2 .

It is a cyclic number.

It is not a de Polignac number, because 21122031989 - 2²⁴ = 21105254773 is a prime.

It is a super-2 number, since 2×21122031989² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21122031389) 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, 10561015994 + 10561015995.

It is an arithmetic number, because the mean of its divisors is an integer number (10561015995).

Almost surely, 2^21122031989 is an apocalyptic number.

It is an amenable number.

21122031989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21122031989 is an equidigital number, since it uses as much as digits as its factorization.

21122031989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 38.

The spelling of 21122031989 in words is "twenty-one billion, one hundred twenty-two million, thirty-one thousand, nine hundred eighty-nine".