231221010121 has 4 divisors (see below), whose sum is σ = 231221972500. Its totient is φ = 231220047744.

The previous prime is 231221010107. The next prime is 231221010133. The reversal of 231221010121 is 121010122132.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 40370855625 + 190850154496 = 200925^2 + 436864^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231221010121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 231221010095 and 231221010104.

It is not an unprimeable number, because it can be changed into a prime (231221010101) 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, 213685 + ... + 712813.

It is an arithmetic number, because the mean of its divisors is an integer number (57805493125).

Almost surely, 2^231221010121 is an apocalyptic number.

It is an amenable number.

231221010121 is a deficient number, since it is larger than the sum of its proper divisors (962379).

231221010121 is an equidigital number, since it uses as much as digits as its factorization.

231221010121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 962378.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 231221010121 its reverse (121010122132), we get a palindrome (352231132253).

The spelling of 231221010121 in words is "two hundred thirty-one billion, two hundred twenty-one million, ten thousand, one hundred twenty-one".