40078809 has 36 divisors (see below), whose sum is σ = 64813840. Its totient is φ = 23794560.

The previous prime is 40078793. The next prime is 40078813. The reversal of 40078809 is 90887004.

40078809 = T₁₁₀ + T₁₁₁ + ... + T₆₂₂.

It is not a de Polignac number, because 40078809 - 2⁴ = 40078793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40078849) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 49014 + ... + 49824.

Almost surely, 2^40078809 is an apocalyptic number.

It is an amenable number.

40078809 is a deficient number, since it is larger than the sum of its proper divisors (24735031).

40078809 is a wasteful number, since it uses less digits than its factorization.

40078809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870 (or 850 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 40078809 is about 6330.7826530375. The cubic root of 40078809 is about 342.2196444814.

The spelling of 40078809 in words is "forty million, seventy-eight thousand, eight hundred nine".