39987685809 has 12 divisors (see below), whose sum is σ = 57763082052. Its totient is φ = 26657030400.

The previous prime is 39987685733. The next prime is 39987685811. The reversal of 39987685809 is 90858678993.

39987685809 is a `hidden beast` number, since 39 + 9 + 8 + 7 + 6 + 8 + 580 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 13235812209 + 26751873600 = 115047^2 + 163560^2 .

It is not a de Polignac number, because 39987685809 - 2²⁰ = 39986637233 is a prime.

It is not an unprimeable number, because it can be changed into a prime (39987680809) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 75289 + ... + 292649.

It is an arithmetic number, because the mean of its divisors is an integer number (4813590171).

Almost surely, 2^39987685809 is an apocalyptic number.

It is an amenable number.

39987685809 is a deficient number, since it is larger than the sum of its proper divisors (17775396243).

39987685809 is a wasteful number, since it uses less digits than its factorization.

39987685809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237808 (or 237805 counting only the distinct ones).

The product of its (nonzero) digits is 235146240, while the sum is 72.

The spelling of 39987685809 in words is "thirty-nine billion, nine hundred eighty-seven million, six hundred eighty-five thousand, eight hundred nine".