399819340784 has 80 divisors (see below), whose sum is σ = 825134688000. Its totient is φ = 187024223232.

The previous prime is 399819340757. The next prime is 399819340787. The reversal of 399819340784 is 487043918993.

It is a self number, because there is not a number n which added to its sum of digits gives 399819340784.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399819340787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68144219 + ... + 68150085.

It is an arithmetic number, because the mean of its divisors is an integer number (10314183600).

Almost surely, 2^399819340784 is an apocalyptic number.

399819340784 is a gapful number since it is divisible by the number (34) 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 399819340784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (412567344000).

399819340784 is an abundant number, since it is smaller than the sum of its proper divisors (425315347216).

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

399819340784 is a wasteful number, since it uses less digits than its factorization.

399819340784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7350 (or 7344 counting only the distinct ones).

The product of its (nonzero) digits is 47029248, while the sum is 65.

The spelling of 399819340784 in words is "three hundred ninety-nine billion, eight hundred nineteen million, three hundred forty thousand, seven hundred eighty-four".