20868539 has 2 divisors, whose sum is σ = 20868540. Its totient is φ = 20868538.

The previous prime is 20868509. The next prime is 20868559. The reversal of 20868539 is 93586802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20868539 - 2²⁴ = 4091323 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20868496 and 20868505.

It is not a weakly prime, because it can be changed into another prime (20868509) 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, 10434269 + 10434270.

It is an arithmetic number, because the mean of its divisors is an integer number (10434270).

Almost surely, 2^20868539 is an apocalyptic number.

20868539 is a deficient number, since it is larger than the sum of its proper divisors (1).

20868539 is an equidigital number, since it uses as much as digits as its factorization.

20868539 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 20868539 is about 4568.2096055238. The cubic root of 20868539 is about 275.3155122491.

The spelling of 20868539 in words is "twenty million, eight hundred sixty-eight thousand, five hundred thirty-nine".