39809878857 has 12 divisors (see below), whose sum is σ = 65717895360. Its totient is φ = 22748502168.

The previous prime is 39809878841. The next prime is 39809878859. The reversal of 39809878857 is 75887890893.

39809878857 is a `hidden beast` number, since 398 + 0 + 98 + 78 + 85 + 7 = 666.

It is not a de Polignac number, because 39809878857 - 2⁴ = 39809878841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (39809878859) 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, 315951357 + ... + 315951482.

It is an arithmetic number, because the mean of its divisors is an integer number (5476491280).

Almost surely, 2^39809878857 is an apocalyptic number.

It is an amenable number.

39809878857 is a deficient number, since it is larger than the sum of its proper divisors (25908016503).

39809878857 is a wasteful number, since it uses less digits than its factorization.

39809878857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631902852 (or 631902849 counting only the distinct ones).

The product of its (nonzero) digits is 243855360, while the sum is 72.

The spelling of 39809878857 in words is "thirty-nine billion, eight hundred nine million, eight hundred seventy-eight thousand, eight hundred fifty-seven".