231012031221 has 72 divisors (see below), whose sum is σ = 373471394400. Its totient is φ = 137191795200.

The previous prime is 231012031181. The next prime is 231012031231. The reversal of 231012031221 is 122130210132.

231012031221 is a `hidden beast` number, since 2 + 310 + 1 + 20 + 312 + 21 = 666.

It is not a de Polignac number, because 231012031221 - 2¹⁹ = 231011506933 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231012031194 and 231012031203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231012031231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 93944290 + ... + 93946748.

It is an arithmetic number, because the mean of its divisors is an integer number (5187102700).

Almost surely, 2^231012031221 is an apocalyptic number.

It is an amenable number.

231012031221 is a deficient number, since it is larger than the sum of its proper divisors (142459363179).

231012031221 is a wasteful number, since it uses less digits than its factorization.

231012031221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4419 (or 4399 counting only the distinct ones).

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

Adding to 231012031221 its reverse (122130210132), we get a palindrome (353142241353).

The spelling of 231012031221 in words is "two hundred thirty-one billion, twelve million, thirty-one thousand, two hundred twenty-one".