394390081536 has 208 divisors, whose sum is σ = 1186746154560. Its totient is φ = 115389890560.

The previous prime is 394390081511. The next prime is 394390081543. The reversal of 394390081536 is 635180093493.

It is a happy number.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3869566 + ... + 3970178.

Almost surely, 2^394390081536 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 394390081536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (593373077280).

394390081536 is an abundant number, since it is smaller than the sum of its proper divisors (792356073024).

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

394390081536 is a wasteful number, since it uses less digits than its factorization.

394390081536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100680 (or 100658 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 51.

The spelling of 394390081536 in words is "three hundred ninety-four billion, three hundred ninety million, eighty-one thousand, five hundred thirty-six".