21920113 has 2 divisors, whose sum is σ = 21920114. Its totient is φ = 21920112.

The previous prime is 21920057. The next prime is 21920141. The reversal of 21920113 is 31102912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21095649 + 824464 = 4593^2 + 908^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21920113 is a prime.

It is not a weakly prime, because it can be changed into another prime (21920413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10960056 + 10960057.

It is an arithmetic number, because the mean of its divisors is an integer number (10960057).

Almost surely, 2^21920113 is an apocalyptic number.

It is an amenable number.

21920113 is a deficient number, since it is larger than the sum of its proper divisors (1).

21920113 is an equidigital number, since it uses as much as digits as its factorization.

21920113 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 21920113 is about 4681.8920320742. The cubic root of 21920113 is about 279.8643603234.

The spelling of 21920113 in words is "twenty-one million, nine hundred twenty thousand, one hundred thirteen".