18991612 has 6 divisors (see below), whose sum is σ = 33235328. Its totient is φ = 9495804.

The previous prime is 18991589. The next prime is 18991627. The reversal of 18991612 is 21619981.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2373948 + ... + 2373955.

Almost surely, 2^18991612 is an apocalyptic number.

It is an amenable number.

18991612 is a deficient number, since it is larger than the sum of its proper divisors (14243716).

18991612 is a wasteful number, since it uses less digits than its factorization.

18991612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4747907 (or 4747905 counting only the distinct ones).

The product of its digits is 7776, while the sum is 37.

The square root of 18991612 is about 4357.9366677362. The cubic root of 18991612 is about 266.8008914553.

The spelling of 18991612 in words is "eighteen million, nine hundred ninety-one thousand, six hundred twelve".