39138864 has 80 divisors (see below), whose sum is σ = 108088320. Its totient is φ = 12176640.

The previous prime is 39138863. The next prime is 39138919. The reversal of 39138864 is 46883193.

It is a happy number.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

Its product of digits (124416) is a multiple of the sum of its prime divisors (972).

It is not an unprimeable number, because it can be changed into a prime (39138863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42699 + ... + 43605.

It is an arithmetic number, because the mean of its divisors is an integer number (1351104).

Almost surely, 2^39138864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 39138864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54044160).

39138864 is an abundant number, since it is smaller than the sum of its proper divisors (68949456).

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

39138864 is a wasteful number, since it uses less digits than its factorization.

39138864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 978 (or 972 counting only the distinct ones).

The product of its digits is 124416, while the sum is 42.

The square root of 39138864 is about 6256.1061372071. The cubic root of 39138864 is about 339.5231608574.

The spelling of 39138864 in words is "thirty-nine million, one hundred thirty-eight thousand, eight hundred sixty-four".