20572161 has 4 divisors (see below), whose sum is σ = 27429552. Its totient is φ = 13714772.

The previous prime is 20572151. The next prime is 20572163. The reversal of 20572161 is 16127502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20572161 - 2⁷ = 20572033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20572163) 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, 3428691 + ... + 3428696.

It is an arithmetic number, because the mean of its divisors is an integer number (6857388).

Almost surely, 2^20572161 is an apocalyptic number.

It is an amenable number.

20572161 is a deficient number, since it is larger than the sum of its proper divisors (6857391).

20572161 is an equidigital number, since it uses as much as digits as its factorization.

20572161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6857390.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 20572161 is about 4535.6544180526. The cubic root of 20572161 is about 274.0059360783.

Adding to 20572161 its reverse (16127502), we get a palindrome (36699663).

The spelling of 20572161 in words is "twenty million, five hundred seventy-two thousand, one hundred sixty-one".