40039945 has 16 divisors (see below), whose sum is σ = 52550208. Its totient is φ = 29045440.

The previous prime is 40039939. The next prime is 40039949. The reversal of 40039945 is 54993004.

It is not a de Polignac number, because 40039945 - 2¹⁹ = 39515657 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 40039945.

It is not an unprimeable number, because it can be changed into a prime (40039949) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29982 + ... + 31288.

It is an arithmetic number, because the mean of its divisors is an integer number (3284388).

Almost surely, 2^40039945 is an apocalyptic number.

It is an amenable number.

40039945 is a deficient number, since it is larger than the sum of its proper divisors (12510263).

40039945 is a wasteful number, since it uses less digits than its factorization.

40039945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1880.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 40039945 is about 6327.7124618617. The cubic root of 40039945 is about 342.1089931100.

The spelling of 40039945 in words is "forty million, thirty-nine thousand, nine hundred forty-five".