40439431 has 2 divisors, whose sum is σ = 40439432. Its totient is φ = 40439430.

The previous prime is 40439419. The next prime is 40439453. The reversal of 40439431 is 13493404.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40439431 - 2⁷ = 40439303 is a prime.

It is a super-2 number, since 2×40439431² = 3270695159207522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 40439431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40439471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20219715 + 20219716.

It is an arithmetic number, because the mean of its divisors is an integer number (20219716).

Almost surely, 2^40439431 is an apocalyptic number.

40439431 is a deficient number, since it is larger than the sum of its proper divisors (1).

40439431 is an equidigital number, since it uses as much as digits as its factorization.

40439431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 40439431 is about 6359.2005000629. The cubic root of 40439431 is about 343.2429918042.

The spelling of 40439431 in words is "forty million, four hundred thirty-nine thousand, four hundred thirty-one".