231222421 has 4 divisors (see below), whose sum is σ = 231252844. Its totient is φ = 231192000.

The previous prime is 231222379. The next prime is 231222487. The reversal of 231222421 is 124222132.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 169364196 + 61858225 = 13014^2 + 7865^2 .

It is a cyclic number.

It is not a de Polignac number, because 231222421 - 2²⁷ = 97004693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231220421) 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 3 ways as a sum of consecutive naturals, for example, 7021 + ... + 22621.

It is an arithmetic number, because the mean of its divisors is an integer number (57813211).

Almost surely, 2^231222421 is an apocalyptic number.

It is an amenable number.

231222421 is a deficient number, since it is larger than the sum of its proper divisors (30423).

231222421 is a wasteful number, since it uses less digits than its factorization.

231222421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30422.

The product of its digits is 384, while the sum is 19.

The square root of 231222421 is about 15205.9995067736. Note that the first 3 decimals coincide. The cubic root of 231222421 is about 613.7761113990.

Adding to 231222421 its reverse (124222132), we get a palindrome (355444553).

The spelling of 231222421 in words is "two hundred thirty-one million, two hundred twenty-two thousand, four hundred twenty-one".