20566231 has 12 divisors (see below), whose sum is σ = 24176208. Its totient is φ = 17442432.

The previous prime is 20566193. The next prime is 20566241. The reversal of 20566231 is 13266502.

20566231 = 104² + 105² + ... + 397².

It is not a de Polignac number, because 20566231 - 2⁹ = 20565719 is a prime.

It is a super-2 number, since 2×20566231² = 845939715090722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20566196 and 20566205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20566241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2590 + ... + 6916.

It is an arithmetic number, because the mean of its divisors is an integer number (2014684).

Almost surely, 2^20566231 is an apocalyptic number.

20566231 is a deficient number, since it is larger than the sum of its proper divisors (3609977).

20566231 is an equidigital number, since it uses as much as digits as its factorization.

20566231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4438 (or 4431 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 20566231 is about 4535.0006615215. Note that the first 3 decimals coincide. The cubic root of 20566231 is about 273.9796058133.

The spelling of 20566231 in words is "twenty million, five hundred sixty-six thousand, two hundred thirty-one".