618221394 has 48 divisors (see below), whose sum is σ = 1537261440. Its totient is φ = 175893120.

The previous prime is 618221377. The next prime is 618221423. The reversal of 618221394 is 493122816.

618221394 is a `hidden beast` number, since 618 + 2 + 2 + 1 + 39 + 4 = 666.

618221394 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20187 + ... + 40545.

It is an arithmetic number, because the mean of its divisors is an integer number (32026280).

Almost surely, 2^618221394 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 618221394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (768630720).

618221394 is an abundant number, since it is smaller than the sum of its proper divisors (919040046).

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

618221394 is a wasteful number, since it uses less digits than its factorization.

618221394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20615 (or 20612 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 618221394 is about 24864.0582769587. The cubic root of 618221394 is about 851.8857298973.

The spelling of 618221394 in words is "six hundred eighteen million, two hundred twenty-one thousand, three hundred ninety-four".