231424221 has 16 divisors (see below), whose sum is σ = 354167424. Its totient is φ = 131672064.

The previous prime is 231424187. The next prime is 231424243. The reversal of 231424221 is 122424132.

It is not a de Polignac number, because 231424221 - 2²⁶ = 164315357 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231424421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18756 + ... + 28541.

It is an arithmetic number, because the mean of its divisors is an integer number (22135464).

Almost surely, 2^231424221 is an apocalyptic number.

231424221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

231424221 is a deficient number, since it is larger than the sum of its proper divisors (122743203).

231424221 is a wasteful number, since it uses less digits than its factorization.

231424221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47540.

The product of its digits is 768, while the sum is 21.

The square root of 231424221 is about 15212.6335984273. The cubic root of 231424221 is about 613.9546177381.

Adding to 231424221 its reverse (122424132), we get a palindrome (353848353).

The spelling of 231424221 in words is "two hundred thirty-one million, four hundred twenty-four thousand, two hundred twenty-one".