42431309 has 4 divisors (see below), whose sum is σ = 42455904. Its totient is φ = 42406716.

The previous prime is 42431273. The next prime is 42431317. The reversal of 42431309 is 90313424.

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 42431309 - 2²⁴ = 25654093 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42431399) 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, 9497 + ... + 13230.

It is an arithmetic number, because the mean of its divisors is an integer number (10613976).

Almost surely, 2^42431309 is an apocalyptic number.

It is an amenable number.

42431309 is a deficient number, since it is larger than the sum of its proper divisors (24595).

42431309 is a wasteful number, since it uses less digits than its factorization.

42431309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24594.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 42431309 is about 6513.9319155177. The cubic root of 42431309 is about 348.7884887914.

The spelling of 42431309 in words is "forty-two million, four hundred thirty-one thousand, three hundred nine".