39999820 has 48 divisors (see below), whose sum is σ = 98058240. Its totient is φ = 13420224.

The previous prime is 39999811. The next prime is 39999821. The reversal of 39999820 is 2899993.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (39999821) 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, 3541 + ... + 9619.

It is an arithmetic number, because the mean of its divisors is an integer number (2042880).

Almost surely, 2^39999820 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 39999820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49029120).

39999820 is an abundant number, since it is smaller than the sum of its proper divisors (58058420).

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

39999820 is a wasteful number, since it uses less digits than its factorization.

39999820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6142 (or 6140 counting only the distinct ones).

The product of its (nonzero) digits is 314928, while the sum is 49.

The square root of 39999820 is about 6324.5410900713. The cubic root of 39999820 is about 341.9946763418.

The spelling of 39999820 in words is "thirty-nine million, nine hundred ninety-nine thousand, eight hundred twenty".