231622721 has 8 divisors (see below), whose sum is σ = 258056064. Its totient is φ = 206085520.

The previous prime is 231622709. The next prime is 231622751. The reversal of 231622721 is 127226132.

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 231622721 - 2²⁶ = 164513857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (231622751) 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, 223490 + ... + 224523.

It is an arithmetic number, because the mean of its divisors is an integer number (32257008).

Almost surely, 2^231622721 is an apocalyptic number.

It is an amenable number.

231622721 is a deficient number, since it is larger than the sum of its proper divisors (26433343).

231622721 is a wasteful number, since it uses less digits than its factorization.

231622721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448071.

The product of its digits is 2016, while the sum is 26.

The square root of 231622721 is about 15219.1563826646. The cubic root of 231622721 is about 614.1301037838.

Adding to 231622721 its reverse (127226132), we get a palindrome (358848853).

The spelling of 231622721 in words is "two hundred thirty-one million, six hundred twenty-two thousand, seven hundred twenty-one".