231331021 has 8 divisors (see below), whose sum is σ = 239825664. Its totient is φ = 222900960.

The previous prime is 231331007. The next prime is 231331049. The reversal of 231331021 is 120133132.

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

It is a cyclic number.

It is not a de Polignac number, because 231331021 - 2¹¹ = 231328973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 231330986 and 231331004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231331081) 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, 8791 + ... + 23236.

It is an arithmetic number, because the mean of its divisors is an integer number (29978208).

Almost surely, 2^231331021 is an apocalyptic number.

It is an amenable number.

231331021 is a deficient number, since it is larger than the sum of its proper divisors (8494643).

231331021 is a wasteful number, since it uses less digits than its factorization.

231331021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32291.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 231331021 is about 15209.5700465201. The cubic root of 231331021 is about 613.8721886631.

Adding to 231331021 its reverse (120133132), we get a palindrome (351464153).

The spelling of 231331021 in words is "two hundred thirty-one million, three hundred thirty-one thousand, twenty-one".