40388809 has 4 divisors (see below), whose sum is σ = 41150916. Its totient is φ = 39626704.

The previous prime is 40388807. The next prime is 40388819. The reversal of 40388809 is 90888304.

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 19713600 + 20675209 = 4440^2 + 4547^2 .

It is a cyclic number.

It is not a de Polignac number, because 40388809 - 2¹ = 40388807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40388807) 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, 380974 + ... + 381079.

It is an arithmetic number, because the mean of its divisors is an integer number (10287729).

Almost surely, 2^40388809 is an apocalyptic number.

It is an amenable number.

40388809 is a deficient number, since it is larger than the sum of its proper divisors (762107).

40388809 is an equidigital number, since it uses as much as digits as its factorization.

40388809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 762106.

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 40388809 is about 6355.2190363511. The cubic root of 40388809 is about 343.0997083668.

The spelling of 40388809 in words is "forty million, three hundred eighty-eight thousand, eight hundred nine".