21913379 has 2 divisors, whose sum is σ = 21913380. Its totient is φ = 21913378.

The previous prime is 21913363. The next prime is 21913387. The reversal of 21913379 is 97331912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21913379 - 2⁴ = 21913363 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21913349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10956689 + 10956690.

It is an arithmetic number, because the mean of its divisors is an integer number (10956690).

Almost surely, 2^21913379 is an apocalyptic number.

21913379 is a deficient number, since it is larger than the sum of its proper divisors (1).

21913379 is an equidigital number, since it uses as much as digits as its factorization.

21913379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10206, while the sum is 35.

The square root of 21913379 is about 4681.1728231288. The cubic root of 21913379 is about 279.8356986764.

The spelling of 21913379 in words is "twenty-one million, nine hundred thirteen thousand, three hundred seventy-nine".