431081991 has 6 divisors (see below), whose sum is σ = 622674000. Its totient is φ = 287387988.

The previous prime is 431081947. The next prime is 431081993. The reversal of 431081991 is 199180134.

It is not a de Polignac number, because 431081991 - 2⁶ = 431081927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (431081993) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23948991 + ... + 23949008.

It is an arithmetic number, because the mean of its divisors is an integer number (103779000).

Almost surely, 2^431081991 is an apocalyptic number.

431081991 is a deficient number, since it is larger than the sum of its proper divisors (191592009).

431081991 is a wasteful number, since it uses less digits than its factorization.

431081991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47898005 (or 47898002 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 431081991 is about 20762.5140818736. The cubic root of 431081991 is about 755.4167784965.

The spelling of 431081991 in words is "four hundred thirty-one million, eighty-one thousand, nine hundred ninety-one".