431105921 has 4 divisors (see below), whose sum is σ = 431805252. Its totient is φ = 430406592.

The previous prime is 431105879. The next prime is 431105957. The reversal of 431105921 is 129501134.

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 123454321 + 307651600 = 11111^2 + 17540^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-431105921 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 (431105321) 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, 348740 + ... + 349973.

It is an arithmetic number, because the mean of its divisors is an integer number (107951313).

Almost surely, 2^431105921 is an apocalyptic number.

It is an amenable number.

431105921 is a deficient number, since it is larger than the sum of its proper divisors (699331).

431105921 is an equidigital number, since it uses as much as digits as its factorization.

431105921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699330.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 431105921 is about 20763.0903528352. The cubic root of 431105921 is about 755.4307563393.

The spelling of 431105921 in words is "four hundred thirty-one million, one hundred five thousand, nine hundred twenty-one".