18913999 has 8 divisors (see below), whose sum is σ = 21026432. Its totient is φ = 16895520.

The previous prime is 18913991. The next prime is 18914011. The reversal of 18913999 is 99931981.

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 18913999 - 2³ = 18913991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18913991) 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, 23064 + ... + 23869.

It is an arithmetic number, because the mean of its divisors is an integer number (2628304).

Almost surely, 2^18913999 is an apocalyptic number.

18913999 is a deficient number, since it is larger than the sum of its proper divisors (2112433).

18913999 is a wasteful number, since it uses less digits than its factorization.

18913999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46977.

The product of its digits is 157464, while the sum is 49.

The square root of 18913999 is about 4349.0227637942. The cubic root of 18913999 is about 266.4369502610.

The spelling of 18913999 in words is "eighteen million, nine hundred thirteen thousand, nine hundred ninety-nine".