21125623117 has 2 divisors, whose sum is σ = 21125623118. Its totient is φ = 21125623116.

The previous prime is 21125623097. The next prime is 21125623163. The reversal of 21125623117 is 71132652112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10695903241 + 10429719876 = 103421^2 + 102126^2 .

It is a cyclic number.

It is not a de Polignac number, because 21125623117 - 2²⁷ = 20991405389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21125653117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562811558 + 10562811559.

It is an arithmetic number, because the mean of its divisors is an integer number (10562811559).

Almost surely, 2^21125623117 is an apocalyptic number.

It is an amenable number.

21125623117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21125623117 is an equidigital number, since it uses as much as digits as its factorization.

21125623117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 31.

The spelling of 21125623117 in words is "twenty-one billion, one hundred twenty-five million, six hundred twenty-three thousand, one hundred seventeen".