20812090 has 16 divisors (see below), whose sum is σ = 40343688. Its totient is φ = 7684416.

The previous prime is 20812039. The next prime is 20812091. The reversal of 20812090 is 9021802.

It can be written as a sum of positive squares in 4 ways, for example, as 6135529 + 14676561 = 2477^2 + 3831^2 .

It is not an unprimeable number, because it can be changed into a prime (20812091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79917 + ... + 80176.

Almost surely, 2^20812090 is an apocalyptic number.

20812090 is a deficient number, since it is larger than the sum of its proper divisors (19531598).

20812090 is a wasteful number, since it uses less digits than its factorization.

20812090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160113.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 20812090 is about 4562.0269617792. The cubic root of 20812090 is about 275.0670470130.

Subtracting from 20812090 its product of nonzero digits (288), we obtain a palindrome (20811802).

Adding to 20812090 its reverse (9021802), we get a palindrome (29833892).

The spelling of 20812090 in words is "twenty million, eight hundred twelve thousand, ninety".