21917113 has 2 divisors, whose sum is σ = 21917114. Its totient is φ = 21917112.

The previous prime is 21917023. The next prime is 21917149. The reversal of 21917113 is 31171912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16548624 + 5368489 = 4068^2 + 2317^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21917113 is a prime.

It is equal to p_1384324 and since 21917113 and 1384324 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21917153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10958556 + 10958557.

It is an arithmetic number, because the mean of its divisors is an integer number (10958557).

Almost surely, 2^21917113 is an apocalyptic number.

It is an amenable number.

21917113 is a deficient number, since it is larger than the sum of its proper divisors (1).

21917113 is an equidigital number, since it uses as much as digits as its factorization.

21917113 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 378, while the sum is 25.

The square root of 21917113 is about 4681.5716378157. The cubic root of 21917113 is about 279.8515922721.

The spelling of 21917113 in words is "twenty-one million, nine hundred seventeen thousand, one hundred thirteen".