231212013221 has 48 divisors (see below), whose sum is σ = 280626353280. Its totient is φ = 186568757760.

The previous prime is 231212013217. The next prime is 231212013229. The reversal of 231212013221 is 122310212132.

It is not a de Polignac number, because 231212013221 - 2² = 231212013217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231212013193 and 231212013202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231212013229) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 76787606 + ... + 76790616.

It is an arithmetic number, because the mean of its divisors is an integer number (5846382360).

Almost surely, 2^231212013221 is an apocalyptic number.

It is an amenable number.

231212013221 is a deficient number, since it is larger than the sum of its proper divisors (49414340059).

231212013221 is a wasteful number, since it uses less digits than its factorization.

231212013221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3386 (or 3363 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 231212013221 its reverse (122310212132), we get a palindrome (353522225353).

The spelling of 231212013221 in words is "two hundred thirty-one billion, two hundred twelve million, thirteen thousand, two hundred twenty-one".