231121320021 has 12 divisors (see below), whose sum is σ = 334042193472. Its totient is φ = 153988439976.

The previous prime is 231121319999. The next prime is 231121320041. The reversal of 231121320021 is 120023121132.

231121320021 is a `hidden beast` number, since 231 + 1 + 213 + 200 + 21 = 666.

It is not a de Polignac number, because 231121320021 - 2¹⁰ = 231121318997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231121319976 and 231121320003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231121320041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7687501 + ... + 7717506.

It is an arithmetic number, because the mean of its divisors is an integer number (27836849456).

Almost surely, 2^231121320021 is an apocalyptic number.

It is an amenable number.

231121320021 is a deficient number, since it is larger than the sum of its proper divisors (102920873451).

231121320021 is a wasteful number, since it uses less digits than its factorization.

231121320021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15406680 (or 15406677 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 231121320021 its reverse (120023121132), we get a palindrome (351144441153).

The spelling of 231121320021 in words is "two hundred thirty-one billion, one hundred twenty-one million, three hundred twenty thousand, twenty-one".