39878979 has 16 divisors (see below), whose sum is σ = 60893952. Its totient is φ = 22740768.

The previous prime is 39878959. The next prime is 39879001. The reversal of 39878979 is 97987893.

It is a happy number.

It is not a de Polignac number, because 39878979 - 2¹⁷ = 39747907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (39878939) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10137 + ... + 13509.

It is an arithmetic number, because the mean of its divisors is an integer number (3805872).

Almost surely, 2^39878979 is an apocalyptic number.

39878979 is a deficient number, since it is larger than the sum of its proper divisors (21014973).

39878979 is a wasteful number, since it uses less digits than its factorization.

39878979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3946.

The product of its digits is 6858432, while the sum is 60.

The square root of 39878979 is about 6314.9805225353. The cubic root of 39878979 is about 341.6499359115.

The spelling of 39878979 in words is "thirty-nine million, eight hundred seventy-eight thousand, nine hundred seventy-nine".