21052079 has 2 divisors, whose sum is σ = 21052080. Its totient is φ = 21052078.

The previous prime is 21052063. The next prime is 21052081. The reversal of 21052079 is 97025012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21052079 - 2⁴ = 21052063 is a prime.

It is a Sophie Germain prime.

Together with 21052081, 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 (21052039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10526039 + 10526040.

It is an arithmetic number, because the mean of its divisors is an integer number (10526040).

Almost surely, 2^21052079 is an apocalyptic number.

21052079 is a deficient number, since it is larger than the sum of its proper divisors (1).

21052079 is an equidigital number, since it uses as much as digits as its factorization.

21052079 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 21052079 is about 4588.2544611214. The cubic root of 21052079 is about 276.1202960519.

The spelling of 21052079 in words is "twenty-one million, fifty-two thousand, seventy-nine".