399440160 has 720 divisors, whose sum is σ = 1783233144. Its totient is φ = 83607552.

The previous prime is 399440137. The next prime is 399440183. The reversal of 399440160 is 61044993.

It is an interprime number because it is at equal distance from previous prime (399440137) and next prime (399440183).

It can be written as a sum of positive squares in 4 ways, for example, as 396328464 + 3111696 = 19908^2 + 1764^2 .

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 10795662 + ... + 10795698.

Almost surely, 2^399440160 is an apocalyptic number.

399440160 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 399440160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (891616572).

399440160 is an abundant number, since it is smaller than the sum of its proper divisors (1383792984).

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

399440160 is a wasteful number, since it uses less digits than its factorization.

399440160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 399440160 is about 19985.9990993695. Note that the first 3 decimals coincide. The cubic root of 399440160 is about 736.4623945359.

Adding to 399440160 its sum of digits (36), we get a square (399440196 = 19986²).

The spelling of 399440160 in words is "three hundred ninety-nine million, four hundred forty thousand, one hundred sixty".