21165007 has 2 divisors, whose sum is σ = 21165008. Its totient is φ = 21165006.

The previous prime is 21164989. The next prime is 21165019. The reversal of 21165007 is 70056112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21165007 - 2¹¹ = 21162959 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21165047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10582503 + 10582504.

It is an arithmetic number, because the mean of its divisors is an integer number (10582504).

Almost surely, 2^21165007 is an apocalyptic number.

21165007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21165007 is an equidigital number, since it uses as much as digits as its factorization.

21165007 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 21165007 is about 4600.5442069390. The cubic root of 21165007 is about 276.6131392712.

The spelling of 21165007 in words is "twenty-one million, one hundred sixty-five thousand, seven".