40518409 has 2 divisors, whose sum is σ = 40518410. Its totient is φ = 40518408.

The previous prime is 40518391. The next prime is 40518419. The reversal of 40518409 is 90481504.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40513225 + 5184 = 6365^2 + 72^2 .

It is a cyclic number.

It is not a de Polignac number, because 40518409 - 2⁷ = 40518281 is a prime.

It is not a weakly prime, because it can be changed into another prime (40518419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20259204 + 20259205.

It is an arithmetic number, because the mean of its divisors is an integer number (20259205).

Almost surely, 2^40518409 is an apocalyptic number.

It is an amenable number.

40518409 is a deficient number, since it is larger than the sum of its proper divisors (1).

40518409 is an equidigital number, since it uses as much as digits as its factorization.

40518409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 40518409 is about 6365.4072139966. The cubic root of 40518409 is about 343.4662970930.

The spelling of 40518409 in words is "forty million, five hundred eighteen thousand, four hundred nine".