399161040 has 80 divisors (see below), whose sum is σ = 1241224128. Its totient is φ = 106114048.

The previous prime is 399160939. The next prime is 399161041. The reversal of 399161040 is 40161993.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 399160992 and 399161010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399161041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 80884 + ... + 85676.

Almost surely, 2^399161040 is an apocalyptic number.

399161040 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 399161040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (620612064).

399161040 is an abundant number, since it is smaller than the sum of its proper divisors (842063088).

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

399161040 is a wasteful number, since it uses less digits than its factorization.

399161040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5156 (or 5150 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 399161040 is about 19979.0149907347. The cubic root of 399161040 is about 736.2908133218.

The spelling of 399161040 in words is "three hundred ninety-nine million, one hundred sixty-one thousand, forty".