20804231 has 4 divisors (see below), whose sum is σ = 23776272. Its totient is φ = 17832192.

The previous prime is 20804159. The next prime is 20804257. The reversal of 20804231 is 13240802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13240802 = 2 ⋅6620401.

It is not a de Polignac number, because 20804231 - 2¹⁰ = 20803207 is a prime.

It is a super-2 number, since 2×20804231² = 865632055002722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20804431) 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, 1486010 + ... + 1486023.

It is an arithmetic number, because the mean of its divisors is an integer number (5944068).

Almost surely, 2^20804231 is an apocalyptic number.

20804231 is a deficient number, since it is larger than the sum of its proper divisors (2972041).

20804231 is an equidigital number, since it uses as much as digits as its factorization.

20804231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2972040.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 20804231 is about 4561.1655308704. The cubic root of 20804231 is about 275.0324193185.

The spelling of 20804231 in words is "twenty million, eight hundred four thousand, two hundred thirty-one".