20620581 has 32 divisors (see below), whose sum is σ = 30336768. Its totient is φ = 12418560.

The previous prime is 20620573. The next prime is 20620583. The reversal of 20620581 is 18502602.

It is not a de Polignac number, because 20620581 - 2³ = 20620573 is a prime.

It is a super-2 number, since 2×20620581² = 850416721555122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20620583) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 104575 + ... + 104771.

It is an arithmetic number, because the mean of its divisors is an integer number (948024).

Almost surely, 2^20620581 is an apocalyptic number.

It is an amenable number.

20620581 is a deficient number, since it is larger than the sum of its proper divisors (9716187).

20620581 is a wasteful number, since it uses less digits than its factorization.

20620581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 20620581 is about 4540.9889891961. The cubic root of 20620581 is about 274.2207404771.

The spelling of 20620581 in words is "twenty million, six hundred twenty thousand, five hundred eighty-one".