20815339 has 2 divisors, whose sum is σ = 20815340. Its totient is φ = 20815338.

The previous prime is 20815337. The next prime is 20815343. The reversal of 20815339 is 93351802.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20815339 - 2¹ = 20815337 is a prime.

Together with 20815337, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20815339.

It is not a weakly prime, because it can be changed into another prime (20815337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10407669 + 10407670.

It is an arithmetic number, because the mean of its divisors is an integer number (10407670).

Almost surely, 2^20815339 is an apocalyptic number.

20815339 is a deficient number, since it is larger than the sum of its proper divisors (1).

20815339 is an equidigital number, since it uses as much as digits as its factorization.

20815339 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 20815339 is about 4562.3830395967. The cubic root of 20815339 is about 275.0813599490.

The spelling of 20815339 in words is "twenty million, eight hundred fifteen thousand, three hundred thirty-nine".