20992789 has 2 divisors, whose sum is σ = 20992790. Its totient is φ = 20992788.

The previous prime is 20992771. The next prime is 20992817. The reversal of 20992789 is 98729902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11444689 + 9548100 = 3383^2 + 3090^2 .

It is a cyclic number.

It is not a de Polignac number, because 20992789 - 2⁵ = 20992757 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20992289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10496394 + 10496395.

It is an arithmetic number, because the mean of its divisors is an integer number (10496395).

Almost surely, 2^20992789 is an apocalyptic number.

It is an amenable number.

20992789 is a deficient number, since it is larger than the sum of its proper divisors (1).

20992789 is an equidigital number, since it uses as much as digits as its factorization.

20992789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 20992789 is about 4581.7888427993. The cubic root of 20992789 is about 275.8608352892.

The spelling of 20992789 in words is "twenty million, nine hundred ninety-two thousand, seven hundred eighty-nine".