231404221 has 4 divisors (see below), whose sum is σ = 245016252. Its totient is φ = 217792192.

The previous prime is 231404209. The next prime is 231404269. The reversal of 231404221 is 122404132.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 210656196 + 20748025 = 14514^2 + 4555^2 .

It is a cyclic number.

It is not a de Polignac number, because 231404221 - 2⁵ = 231404189 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 (231401221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6805990 + ... + 6806023.

It is an arithmetic number, because the mean of its divisors is an integer number (61254063).

Almost surely, 2^231404221 is an apocalyptic number.

It is an amenable number.

231404221 is a deficient number, since it is larger than the sum of its proper divisors (13612031).

231404221 is a wasteful number, since it uses less digits than its factorization.

231404221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13612030.

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

The square root of 231404221 is about 15211.9762358479. The cubic root of 231404221 is about 613.9369309606.

Adding to 231404221 its reverse (122404132), we get a palindrome (353808353).

The spelling of 231404221 in words is "two hundred thirty-one million, four hundred four thousand, two hundred twenty-one".