431803921 has 4 divisors (see below), whose sum is σ = 432085312. Its totient is φ = 431522532.

The previous prime is 431803891. The next prime is 431803951. The reversal of 431803921 is 129308134.

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, and also an emirpimes, since its reverse is a distinct semiprime: 129308134 = 2 ⋅64654067.

It is an interprime number because it is at equal distance from previous prime (431803891) and next prime (431803951).

It is a cyclic number.

It is not a de Polignac number, because 431803921 - 2¹⁷ = 431672849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (431803951) 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, 138381 + ... + 141466.

It is an arithmetic number, because the mean of its divisors is an integer number (108021328).

Almost surely, 2^431803921 is an apocalyptic number.

It is an amenable number.

431803921 is a deficient number, since it is larger than the sum of its proper divisors (281391).

431803921 is a wasteful number, since it uses less digits than its factorization.

431803921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281390.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 431803921 is about 20779.8922278245. The cubic root of 431803921 is about 755.8382403788.

The spelling of 431803921 in words is "four hundred thirty-one million, eight hundred three thousand, nine hundred twenty-one".