399980021760 has 672 divisors, whose sum is σ = 1570051304640. Its totient is φ = 96944947200.

The previous prime is 399980021737. The next prime is 399980021821. The reversal of 399980021760 is 67120089993.

399980021760 is a `hidden beast` number, since 399 + 9 + 80 + 0 + 2 + 176 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 399980021697 and 399980021706.

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 55 ways as a sum of consecutive naturals, for example, 82112125 + ... + 82116995.

It is an arithmetic number, because the mean of its divisors is an integer number (2336385870).

Almost surely, 2^399980021760 is an apocalyptic number.

399980021760 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 399980021760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (785025652320).

399980021760 is an abundant number, since it is smaller than the sum of its proper divisors (1170071282880).

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

399980021760 is an equidigital number, since it uses as much as digits as its factorization.

399980021760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4927 (or 4892 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 54.

The spelling of 399980021760 in words is "three hundred ninety-nine billion, nine hundred eighty million, twenty-one thousand, seven hundred sixty".