231021213 has 8 divisors (see below), whose sum is σ = 313078176. Its totient is φ = 151489200.

The previous prime is 231021191. The next prime is 231021227. The reversal of 231021213 is 312120132.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 231021213 - 2⁸ = 231020957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231021192 and 231021201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231021233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 631023 + ... + 631388.

It is an arithmetic number, because the mean of its divisors is an integer number (39134772).

Almost surely, 2^231021213 is an apocalyptic number.

It is an amenable number.

231021213 is a deficient number, since it is larger than the sum of its proper divisors (82056963).

231021213 is a wasteful number, since it uses less digits than its factorization.

231021213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1262475.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 231021213 is about 15199.3819940154. The cubic root of 231021213 is about 613.5980252910.

Adding to 231021213 its reverse (312120132), we get a palindrome (543141345).

The spelling of 231021213 in words is "two hundred thirty-one million, twenty-one thousand, two hundred thirteen".