431221321 has 4 divisors (see below), whose sum is σ = 453917200. Its totient is φ = 408525444.

The previous prime is 431221309. The next prime is 431221327. The reversal of 431221321 is 123122134.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 431221321 - 2¹¹ = 431219273 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 22695859 = 431221321 / (4 + 3 + 1 + 2 + 2 + 1 + 3 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (431221327) 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, 11347911 + ... + 11347948.

It is an arithmetic number, because the mean of its divisors is an integer number (113479300).

Almost surely, 2^431221321 is an apocalyptic number.

It is an amenable number.

431221321 is a deficient number, since it is larger than the sum of its proper divisors (22695879).

431221321 is a wasteful number, since it uses less digits than its factorization.

431221321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22695878.

The product of its digits is 288, while the sum is 19.

The square root of 431221321 is about 20765.8691366386. The cubic root of 431221321 is about 755.4981558094.

Adding to 431221321 its reverse (123122134), we get a palindrome (554343455).

The spelling of 431221321 in words is "four hundred thirty-one million, two hundred twenty-one thousand, three hundred twenty-one".