231244021 has 4 divisors (see below), whose sum is σ = 231469344. Its totient is φ = 231018700.

The previous prime is 231244009. The next prime is 231244033. The reversal of 231244021 is 120442132.

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 an interprime number because it is at equal distance from previous prime (231244009) and next prime (231244033).

It is a cyclic number.

It is not a de Polignac number, because 231244021 - 2⁵ = 231243989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 231244021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231244051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111115 + ... + 113176.

It is an arithmetic number, because the mean of its divisors is an integer number (57867336).

Almost surely, 2^231244021 is an apocalyptic number.

It is an amenable number.

231244021 is a deficient number, since it is larger than the sum of its proper divisors (225323).

231244021 is a wasteful number, since it uses less digits than its factorization.

231244021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225322.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 231244021 is about 15206.7097361658. The cubic root of 231244021 is about 613.7952230854.

Adding to 231244021 its reverse (120442132), we get a palindrome (351686153).

The spelling of 231244021 in words is "two hundred thirty-one million, two hundred forty-four thousand, twenty-one".