40015909 has 4 divisors (see below), whose sum is σ = 42369804. Its totient is φ = 37662016.

The previous prime is 40015903. The next prime is 40015961. The reversal of 40015909 is 90951004.

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

It can be written as a sum of positive squares in 2 ways, for example, as 33385284 + 6630625 = 5778^2 + 2575^2 .

It is a cyclic number.

It is not a de Polignac number, because 40015909 - 2¹³ = 40007717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40015903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1176922 + ... + 1176955.

It is an arithmetic number, because the mean of its divisors is an integer number (10592451).

Almost surely, 2^40015909 is an apocalyptic number.

It is an amenable number.

40015909 is a deficient number, since it is larger than the sum of its proper divisors (2353895).

40015909 is a wasteful number, since it uses less digits than its factorization.

40015909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2353894.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 40015909 is about 6325.8129121877. The cubic root of 40015909 is about 342.0405233379.

The spelling of 40015909 in words is "forty million, fifteen thousand, nine hundred nine".