399999860 has 24 divisors (see below), whose sum is σ = 904615656. Its totient is φ = 147692160.

The previous prime is 399999857. The next prime is 399999869. The reversal of 399999860 is 68999993.

It can be written as a sum of positive squares in 4 ways, for example, as 30514576 + 369485284 = 5524^2 + 19222^2 .

It is a junction number, because it is equal to n+sod(n) for n = 399999793 and 399999802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399999869) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 768971 + ... + 769490.

It is an arithmetic number, because the mean of its divisors is an integer number (37692319).

Almost surely, 2^399999860 is an apocalyptic number.

It is an amenable number.

399999860 is an abundant number, since it is smaller than the sum of its proper divisors (504615796).

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

399999860 is a wasteful number, since it uses less digits than its factorization.

399999860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1538483 (or 1538481 counting only the distinct ones).

The product of its (nonzero) digits is 8503056, while the sum is 62.

The square root of 399999860 is about 19999.9964999997. The cubic root of 399999860 is about 736.8062137673.

The spelling of 399999860 in words is "three hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred sixty".