18837993 has 8 divisors (see below), whose sum is σ = 25142656. Its totient is φ = 12546000.

The previous prime is 18837991. The next prime is 18838009. The reversal of 18837993 is 39973881.

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

It is not a de Polignac number, because 18837993 - 2¹ = 18837991 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18837991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1143 + ... + 6243.

It is an arithmetic number, because the mean of its divisors is an integer number (3142832).

Almost surely, 2^18837993 is an apocalyptic number.

It is an amenable number.

18837993 is a deficient number, since it is larger than the sum of its proper divisors (6304663).

18837993 is a wasteful number, since it uses less digits than its factorization.

18837993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6335.

The product of its digits is 326592, while the sum is 48.

The square root of 18837993 is about 4340.2756824884. The cubic root of 18837993 is about 266.0795783914.

The spelling of 18837993 in words is "eighteen million, eight hundred thirty-seven thousand, nine hundred ninety-three".