39999999 has 8 divisors (see below), whose sum is σ = 57435952.
Its totient is φ = 24615360.
The previous prime is 39999983. The next prime is 40000003. The reversal of 39999999 is 99999993.
It is a sphenic number, since it is the product of 3 distinct primes.
It is not a de Polignac number, because 39999999 - 24 = 39999983 is a prime.
It is a Duffinian number.
39999999 is a modest number, since divided by 9999 gives 3999 as remainder.
It is a plaindrome in base 10.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (39999919) by changing a digit.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 512782 + ... + 512859.
It is an arithmetic number, because the mean of its divisors is an integer number (7179494).
Almost surely, 239999999 is an apocalyptic number.
39999999 is a gapful number since it is divisible by the number (39) formed by its first and last digit.
39999999 is a deficient number, since it is larger than the sum of its proper divisors (17435953).
39999999 is a wasteful number, since it uses less digits than its factorization.
39999999 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1025657.
The product of its digits is 14348907, while the sum is 66.
The square root of 39999999 is about 6324.5552412798.
Note that the first 3 decimals coincide.
The cubic root of 39999999 is about 341.9951864854.
The spelling of 39999999 in words is "thirty-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".