20155231 has 4 divisors (see below), whose sum is σ = 20646864. Its totient is φ = 19663600.

The previous prime is 20155169. The next prime is 20155249. The reversal of 20155231 is 13255102.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20155231 - 2¹⁹ = 19630943 is a prime.

It is a super-2 number, since 2×20155231² = 812466673326722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20155199 and 20155208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20155271) 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, 245755 + ... + 245836.

It is an arithmetic number, because the mean of its divisors is an integer number (5161716).

Almost surely, 2^20155231 is an apocalyptic number.

20155231 is a deficient number, since it is larger than the sum of its proper divisors (491633).

20155231 is an equidigital number, since it uses as much as digits as its factorization.

20155231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491632.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 20155231 is about 4489.4577623584. The cubic root of 20155231 is about 272.1422221551.

The spelling of 20155231 in words is "twenty million, one hundred fifty-five thousand, two hundred thirty-one".