399981708 has 108 divisors (see below), whose sum is σ = 1183133952. Its totient is φ = 113601600.

The previous prime is 399981689. The next prime is 399981721. The reversal of 399981708 is 807189993.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 346933 + ... + 348083.

It is an arithmetic number, because the mean of its divisors is an integer number (10954944).

Almost surely, 2^399981708 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 399981708, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (591566976).

399981708 is an abundant number, since it is smaller than the sum of its proper divisors (783152244).

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

399981708 is a wasteful number, since it uses less digits than its factorization.

399981708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1372 (or 1360 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 54.

The square root of 399981708 is about 19999.5426947718. The cubic root of 399981708 is about 736.7950681728.

It can be divided in two parts, 399981 and 708, that added together give a square (400689 = 633²).

The spelling of 399981708 in words is "three hundred ninety-nine million, nine hundred eighty-one thousand, seven hundred eight".