21973379 has 2 divisors, whose sum is σ = 21973380. Its totient is φ = 21973378.

The previous prime is 21973363. The next prime is 21973423. The reversal of 21973379 is 97337912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21973379 - 2⁴ = 21973363 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21973309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10986689 + 10986690.

It is an arithmetic number, because the mean of its divisors is an integer number (10986690).

Almost surely, 2^21973379 is an apocalyptic number.

21973379 is a deficient number, since it is larger than the sum of its proper divisors (1).

21973379 is an equidigital number, since it uses as much as digits as its factorization.

21973379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 71442, while the sum is 41.

The square root of 21973379 is about 4687.5770926994. The cubic root of 21973379 is about 280.0908676166.

The spelling of 21973379 in words is "twenty-one million, nine hundred seventy-three thousand, three hundred seventy-nine".