399173760 has 192 divisors, whose sum is σ = 1416406680. Its totient is φ = 103514112.

The previous prime is 399173741. The next prime is 399173771. The reversal of 399173760 is 67371993.

It can be written as a sum of positive squares in 4 ways, for example, as 291180096 + 107993664 = 17064^2 + 10392^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 212184 + ... + 214056.

Almost surely, 2^399173760 is an apocalyptic number.

399173760 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399173760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (708203340).

399173760 is an abundant number, since it is smaller than the sum of its proper divisors (1017232920).

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

399173760 is a wasteful number, since it uses less digits than its factorization.

399173760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1935 (or 1920 counting only the distinct ones).

The product of its (nonzero) digits is 214326, while the sum is 45.

The square root of 399173760 is about 19979.3333222107. Note that the first 4 decimals coincide. The cubic root of 399173760 is about 736.2986343253.

The spelling of 399173760 in words is "three hundred ninety-nine million, one hundred seventy-three thousand, seven hundred sixty".