40431509 has 2 divisors, whose sum is σ = 40431510. Its totient is φ = 40431508.

The previous prime is 40431499. The next prime is 40431511. The reversal of 40431509 is 90513404.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34550884 + 5880625 = 5878^2 + 2425^2 .

It is a cyclic number.

It is not a de Polignac number, because 40431509 - 2²⁰ = 39382933 is a prime.

Together with 40431511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40431529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20215754 + 20215755.

It is an arithmetic number, because the mean of its divisors is an integer number (20215755).

Almost surely, 2^40431509 is an apocalyptic number.

It is an amenable number.

40431509 is a deficient number, since it is larger than the sum of its proper divisors (1).

40431509 is an equidigital number, since it uses as much as digits as its factorization.

40431509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 40431509 is about 6358.5775925123. The cubic root of 40431509 is about 343.2205768123.

It can be divided in two parts, 404 and 31509, that added together give a palindrome (31913).

The spelling of 40431509 in words is "forty million, four hundred thirty-one thousand, five hundred nine".