18506993 has 8 divisors (see below), whose sum is σ = 19100928. Its totient is φ = 17918064.

The previous prime is 18506987. The next prime is 18507011. The reversal of 18506993 is 39960581.

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

It is not a de Polignac number, because 18506993 - 2⁴ = 18506977 is a prime.

It is a super-3 number, since 3×18506993³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18506993.

It is not an unprimeable number, because it can be changed into a prime (18506903) 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, 7130 + ... + 9372.

It is an arithmetic number, because the mean of its divisors is an integer number (2387616).

Almost surely, 2^18506993 is an apocalyptic number.

It is an amenable number.

18506993 is a deficient number, since it is larger than the sum of its proper divisors (593935).

18506993 is a wasteful number, since it uses less digits than its factorization.

18506993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2503.

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 18506993 is about 4301.9754764526. The cubic root of 18506993 is about 264.5119437433.

The spelling of 18506993 in words is "eighteen million, five hundred six thousand, nine hundred ninety-three".