21590329 has 2 divisors, whose sum is σ = 21590330. Its totient is φ = 21590328.

The previous prime is 21590321. The next prime is 21590339. The reversal of 21590329 is 92309512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20430400 + 1159929 = 4520^2 + 1077^2 .

It is a cyclic number.

It is not a de Polignac number, because 21590329 - 2³ = 21590321 is a prime.

It is a super-3 number, since 3×21590329³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 21590329.

It is not a weakly prime, because it can be changed into another prime (21590321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10795164 + 10795165.

It is an arithmetic number, because the mean of its divisors is an integer number (10795165).

Almost surely, 2^21590329 is an apocalyptic number.

It is an amenable number.

21590329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21590329 is an equidigital number, since it uses as much as digits as its factorization.

21590329 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 21590329 is about 4646.5394650213. The cubic root of 21590329 is about 278.4537601032.

The spelling of 21590329 in words is "twenty-one million, five hundred ninety thousand, three hundred twenty-nine".