21274679 has 2 divisors, whose sum is σ = 21274680. Its totient is φ = 21274678.

The previous prime is 21274651. The next prime is 21274681. The reversal of 21274679 is 97647212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21274679 - 2¹² = 21270583 is a prime.

It is a super-2 number, since 2×21274679² = 905223933106082, which contains 22 as substring.

Together with 21274681, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21274619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10637339 + 10637340.

It is an arithmetic number, because the mean of its divisors is an integer number (10637340).

Almost surely, 2^21274679 is an apocalyptic number.

21274679 is a deficient number, since it is larger than the sum of its proper divisors (1).

21274679 is an equidigital number, since it uses as much as digits as its factorization.

21274679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42336, while the sum is 38.

The square root of 21274679 is about 4612.4482652925. The cubic root of 21274679 is about 277.0900974147.

The spelling of 21274679 in words is "twenty-one million, two hundred seventy-four thousand, six hundred seventy-nine".