394120818 has 144 divisors (see below), whose sum is σ = 1099851480. Its totient is φ = 101025792.

The previous prime is 394120813. The next prime is 394120829. The reversal of 394120818 is 818021493.

It can be written as a sum of positive squares in 4 ways, for example, as 236944449 + 157176369 = 15393^2 + 12537^2 .

It is not an unprimeable number, because it can be changed into a prime (394120813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 423778 + ... + 424706.

Almost surely, 2^394120818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 394120818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (549925740).

394120818 is an abundant number, since it is smaller than the sum of its proper divisors (705730662).

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

394120818 is a wasteful number, since it uses less digits than its factorization.

394120818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1001 (or 991 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 394120818 is about 19852.4763694608. The cubic root of 394120818 is about 733.1786194738.

The spelling of 394120818 in words is "three hundred ninety-four million, one hundred twenty thousand, eight hundred eighteen".