20899789 has 2 divisors, whose sum is σ = 20899790. Its totient is φ = 20899788.

The previous prime is 20899757. The next prime is 20899811. The reversal of 20899789 is 98799802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13446889 + 7452900 = 3667^2 + 2730^2 .

It is a cyclic number.

It is not a de Polignac number, because 20899789 - 2⁵ = 20899757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20899189) 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, 10449894 + 10449895.

It is an arithmetic number, because the mean of its divisors is an integer number (10449895).

Almost surely, 2^20899789 is an apocalyptic number.

It is an amenable number.

20899789 is a deficient number, since it is larger than the sum of its proper divisors (1).

20899789 is an equidigital number, since it uses as much as digits as its factorization.

20899789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 653184, while the sum is 52.

The square root of 20899789 is about 4571.6287032085. The cubic root of 20899789 is about 275.4528692338.

The spelling of 20899789 in words is "twenty million, eight hundred ninety-nine thousand, seven hundred eighty-nine".