181118993 has 8 divisors (see below), whose sum is σ = 197723136. Its totient is φ = 164538000.

The previous prime is 181118981. The next prime is 181119049. The reversal of 181118993 is 399811181.

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

It is not a de Polignac number, because 181118993 - 2⁶ = 181118929 is a prime.

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 181118993.

It is not an unprimeable number, because it can be changed into a prime (181118893) 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, 13343 + ... + 23243.

It is an arithmetic number, because the mean of its divisors is an integer number (24715392).

Almost surely, 2^181118993 is an apocalyptic number.

It is an amenable number.

181118993 is a deficient number, since it is larger than the sum of its proper divisors (16604143).

181118993 is a wasteful number, since it uses less digits than its factorization.

181118993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11575.

The product of its digits is 15552, while the sum is 41.

The square root of 181118993 is about 13458.0456604962. The cubic root of 181118993 is about 565.7892152968.

The spelling of 181118993 in words is "one hundred eighty-one million, one hundred eighteen thousand, nine hundred ninety-three".