18191842 has 8 divisors (see below), whose sum is σ = 27309996. Its totient is φ = 9088512.

The previous prime is 18191837. The next prime is 18191869. The reversal of 18191842 is 24819181.

It can be written as a sum of positive squares in 2 ways, for example, as 18156121 + 35721 = 4261^2 + 189^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 18191798 and 18191807.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178 + ... + 6034.

Almost surely, 2^18191842 is an apocalyptic number.

18191842 is a deficient number, since it is larger than the sum of its proper divisors (9118154).

18191842 is a wasteful number, since it uses less digits than its factorization.

18191842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7412.

The product of its digits is 4608, while the sum is 34.

The square root of 18191842 is about 4265.1895620242. The cubic root of 18191842 is about 263.0019035365.

The spelling of 18191842 in words is "eighteen million, one hundred ninety-one thousand, eight hundred forty-two".