21113297 has 2 divisors, whose sum is σ = 21113298. Its totient is φ = 21113296.

The previous prime is 21113251. The next prime is 21113299. The reversal of 21113297 is 79231112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18524416 + 2588881 = 4304^2 + 1609^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113297 - 2⁸ = 21113041 is a prime.

Together with 21113299, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21113299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556648 + 10556649.

It is an arithmetic number, because the mean of its divisors is an integer number (10556649).

Almost surely, 2^21113297 is an apocalyptic number.

It is an amenable number.

21113297 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113297 is an equidigital number, since it uses as much as digits as its factorization.

21113297 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 26.

The square root of 21113297 is about 4594.9207827774. The cubic root of 21113297 is about 276.3876833241.

The spelling of 21113297 in words is "twenty-one million, one hundred thirteen thousand, two hundred ninety-seven".