231221111021 has 8 divisors (see below), whose sum is σ = 243471806400. Its totient is φ = 218978532000.

The previous prime is 231221110997. The next prime is 231221111047. The reversal of 231221111021 is 120111122132.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231221111021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231221111221) 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, 1970561 + ... + 2084598.

It is an arithmetic number, because the mean of its divisors is an integer number (30433975800).

Almost surely, 2^231221111021 is an apocalyptic number.

It is an amenable number.

231221111021 is a deficient number, since it is larger than the sum of its proper divisors (12250695379).

231221111021 is a wasteful number, since it uses less digits than its factorization.

231221111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4058179.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 231221111021 its reverse (120111122132), we get a palindrome (351332233153).

It can be divided in two parts, 2312211 and 11021, that added together give a palindrome (2323232).

The spelling of 231221111021 in words is "two hundred thirty-one billion, two hundred twenty-one million, one hundred eleven thousand, twenty-one".