399638333056 has 64 divisors (see below), whose sum is σ = 821996098560. Its totient is φ = 193410201600.

The previous prime is 399638333053. The next prime is 399638333113. The reversal of 399638333056 is 650333836993.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (399638333053) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 366691 + ... + 966301.

It is an arithmetic number, because the mean of its divisors is an integer number (12843689040).

Almost surely, 2^399638333056 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399638333056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (410998049280).

399638333056 is an abundant number, since it is smaller than the sum of its proper divisors (422357765504).

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

399638333056 is a wasteful number, since it uses less digits than its factorization.

399638333056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 599793 (or 599781 counting only the distinct ones).

The product of its (nonzero) digits is 28343520, while the sum is 58.

The spelling of 399638333056 in words is "three hundred ninety-nine billion, six hundred thirty-eight million, three hundred thirty-three thousand, fifty-six".