18937993 has 8 divisors (see below), whose sum is σ = 20399616. Its totient is φ = 17529600.

The previous prime is 18937991. The next prime is 18938011. The reversal of 18937993 is 39973981.

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

It is a cyclic number.

It is not a de Polignac number, because 18937993 - 2¹ = 18937991 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18937991) 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, 12568 + ... + 13993.

It is an arithmetic number, because the mean of its divisors is an integer number (2549952).

Almost surely, 2^18937993 is an apocalyptic number.

It is an amenable number.

18937993 is a deficient number, since it is larger than the sum of its proper divisors (1461623).

18937993 is a wasteful number, since it uses less digits than its factorization.

18937993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26615.

The product of its digits is 367416, while the sum is 49.

The square root of 18937993 is about 4351.7804402336. The cubic root of 18937993 is about 266.5495685529.

The spelling of 18937993 in words is "eighteen million, nine hundred thirty-seven thousand, nine hundred ninety-three".