231221415 has 32 divisors (see below), whose sum is σ = 392403456. Its totient is φ = 116012160.

The previous prime is 231221411. The next prime is 231221453. The reversal of 231221415 is 514122132.

It is not a de Polignac number, because 231221415 - 2² = 231221411 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231221391 and 231221400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231221411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15552 + ... + 26538.

It is an arithmetic number, because the mean of its divisors is an integer number (12262608).

Almost surely, 2^231221415 is an apocalyptic number.

231221415 is a deficient number, since it is larger than the sum of its proper divisors (161182041).

231221415 is a wasteful number, since it uses less digits than its factorization.

231221415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11079.

The product of its digits is 480, while the sum is 21.

The square root of 231221415 is about 15205.9664276888. The cubic root of 231221415 is about 613.7752212609.

Adding to 231221415 its reverse (514122132), we get a palindrome (745343547).

The spelling of 231221415 in words is "two hundred thirty-one million, two hundred twenty-one thousand, four hundred fifteen".