39999978 has 24 divisors (see below), whose sum is σ = 91228800. Its totient is φ = 12631464.

The previous prime is 39999943. The next prime is 39999979. The reversal of 39999978 is 87999993.

39999978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (39999979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58138 + ... + 58821.

It is an arithmetic number, because the mean of its divisors is an integer number (3801200).

Almost surely, 2^39999978 is an apocalyptic number.

39999978 is a gapful number since it is divisible by the number (38) formed by its first and last digit.

39999978 is an abundant number, since it is smaller than the sum of its proper divisors (51228822).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

39999978 is a wasteful number, since it uses less digits than its factorization.

39999978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116986 (or 116983 counting only the distinct ones).

The product of its digits is 9920232, while the sum is 63.

The square root of 39999978 is about 6324.5535810838. The cubic root of 39999978 is about 341.9951266362.

The spelling of 39999978 in words is "thirty-nine million, nine hundred ninety-nine thousand, nine hundred seventy-eight".