17991842 has 48 divisors (see below), whose sum is σ = 32602176. Its totient is φ = 7365600.

The previous prime is 17991833. The next prime is 17991847. The reversal of 17991842 is 24819971.

It is a self number, because there is not a number n which added to its sum of digits gives 17991842.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17991847) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 486248 + ... + 486284.

It is an arithmetic number, because the mean of its divisors is an integer number (679212).

Almost surely, 2^17991842 is an apocalyptic number.

17991842 is a deficient number, since it is larger than the sum of its proper divisors (14610334).

17991842 is a wasteful number, since it uses less digits than its factorization.

17991842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 104 counting only the distinct ones).

The product of its digits is 36288, while the sum is 41.

The square root of 17991842 is about 4241.6791486391. The cubic root of 17991842 is about 262.0345408300.

The spelling of 17991842 in words is "seventeen million, nine hundred ninety-one thousand, eight hundred forty-two".