20920839 has 4 divisors (see below), whose sum is σ = 27894456. Its totient is φ = 13947224.

The previous prime is 20920819. The next prime is 20920841. The reversal of 20920839 is 93802902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20920839 - 2⁵ = 20920807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20920819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3486804 + ... + 3486809.

It is an arithmetic number, because the mean of its divisors is an integer number (6973614).

Almost surely, 2^20920839 is an apocalyptic number.

20920839 is a deficient number, since it is larger than the sum of its proper divisors (6973617).

20920839 is an equidigital number, since it uses as much as digits as its factorization.

20920839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6973616.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 20920839 is about 4573.9303667634. The cubic root of 20920839 is about 275.5453157386.

The spelling of 20920839 in words is "twenty million, nine hundred twenty thousand, eight hundred thirty-nine".