40391431 has 4 divisors (see below), whose sum is σ = 40436872. Its totient is φ = 40345992.

The previous prime is 40391423. The next prime is 40391467. The reversal of 40391431 is 13419304.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 40391431 - 2³ = 40391423 is a prime.

It is a super-2 number, since 2×40391431² = 3262935396455522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40391396 and 40391405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40391231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21360 + ... + 23173.

It is an arithmetic number, because the mean of its divisors is an integer number (10109218).

Almost surely, 2^40391431 is an apocalyptic number.

40391431 is a deficient number, since it is larger than the sum of its proper divisors (45441).

40391431 is an equidigital number, since it uses as much as digits as its factorization.

40391431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45440.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 40391431 is about 6355.4253201497. The cubic root of 40391431 is about 343.1071327664.

The spelling of 40391431 in words is "forty million, three hundred ninety-one thousand, four hundred thirty-one".