21590339 has 2 divisors, whose sum is σ = 21590340. Its totient is φ = 21590338.

The previous prime is 21590329. The next prime is 21590369. The reversal of 21590339 is 93309512.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21590339 is a prime.

It is a super-2 number, since 2×21590339² = 932285476269842, which contains 22 as substring.

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 (21590329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10795169 + 10795170.

It is an arithmetic number, because the mean of its divisors is an integer number (10795170).

Almost surely, 2^21590339 is an apocalyptic number.

21590339 is a deficient number, since it is larger than the sum of its proper divisors (1).

21590339 is an equidigital number, since it uses as much as digits as its factorization.

21590339 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7290, while the sum is 32.

The square root of 21590339 is about 4646.5405410908. The cubic root of 21590339 is about 278.4538030937.

The spelling of 21590339 in words is "twenty-one million, five hundred ninety thousand, three hundred thirty-nine".