40005439 has 2 divisors, whose sum is σ = 40005440. Its totient is φ = 40005438.

The previous prime is 40005409. The next prime is 40005467. The reversal of 40005439 is 93450004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 40005439 - 2⁷ = 40005311 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40005409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20002719 + 20002720.

It is an arithmetic number, because the mean of its divisors is an integer number (20002720).

Almost surely, 2^40005439 is an apocalyptic number.

40005439 is a deficient number, since it is larger than the sum of its proper divisors (1).

40005439 is an equidigital number, since it uses as much as digits as its factorization.

40005439 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 40005439 is about 6324.9852964256. The cubic root of 40005439 is about 342.0106895648.

The spelling of 40005439 in words is "forty million, five thousand, four hundred thirty-nine".