18199640 has 16 divisors (see below), whose sum is σ = 40949280. Its totient is φ = 7279840.

The previous prime is 18199637. The next prime is 18199661. The reversal of 18199640 is 4699181.

It is a happy number.

It is a super-2 number, since 2×18199640² = 662453792259200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18199594 and 18199603.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 227456 + ... + 227535.

It is an arithmetic number, because the mean of its divisors is an integer number (2559330).

Almost surely, 2^18199640 is an apocalyptic number.

18199640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18199640 is an abundant number, since it is smaller than the sum of its proper divisors (22749640).

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

18199640 is a wasteful number, since it uses less digits than its factorization.

18199640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455002 (or 454998 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 18199640 is about 4266.1036086809. The cubic root of 18199640 is about 263.0394770795.

The spelling of 18199640 in words is "eighteen million, one hundred ninety-nine thousand, six hundred forty".