231220021013213 has 4 divisors (see below), whose sum is σ = 231239989935840. Its totient is φ = 231200052090588.

The previous prime is 231220021013207. The next prime is 231220021013221. The reversal of 231220021013213 is 312310120022132.

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 a cyclic number.

It is not a de Polignac number, because 231220021013213 - 2²⁸ = 231219752577757 is a prime.

It is a super-2 number, since 2×231220021013213² (a number of 30 digits) 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 (231220021013243) 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, 9984443945 + ... + 9984467102.

It is an arithmetic number, because the mean of its divisors is an integer number (57809997483960).

Almost surely, 2^{231220021013213} is an apocalyptic number.

It is an amenable number.

231220021013213 is a deficient number, since it is larger than the sum of its proper divisors (19968922627).

231220021013213 is a wasteful number, since it uses less digits than its factorization.

231220021013213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19968922626.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 231220021013213 its reverse (312310120022132), we get a palindrome (543530141035345).

The spelling of 231220021013213 in words is "two hundred thirty-one trillion, two hundred twenty billion, twenty-one million, thirteen thousand, two hundred thirteen".