399999639980016 has 120 divisors (see below), whose sum is σ = 1129415438165040. Its totient is φ = 132145617881088.

The previous prime is 399999639979981. The next prime is 399999639980047. The reversal of 399999639980016 is 610089936999993.

399999639980016 is a `hidden beast` number, since 39 + 9 + 99 + 96 + 399 + 8 + 0 + 0 + 16 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 399999639979899 and 399999639979908.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 283682475 + ... + 285089013.

It is an arithmetic number, because the mean of its divisors is an integer number (9411795318042).

Almost surely, 2^{399999639980016} is an apocalyptic number.

399999639980016 is a gapful number since it is divisible by the number (36) 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 399999639980016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (564707719082520).

399999639980016 is an abundant number, since it is smaller than the sum of its proper divisors (729415798185024).

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

399999639980016 is a wasteful number, since it uses less digits than its factorization.

399999639980016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1424143 (or 1424134 counting only the distinct ones).

The product of its (nonzero) digits is 12397455648, while the sum is 90.

The spelling of 399999639980016 in words is "three hundred ninety-nine trillion, nine hundred ninety-nine billion, six hundred thirty-nine million, nine hundred eighty thousand, sixteen".