818993 has 8 divisors (see below), whose sum is σ = 948480. Its totient is φ = 692640.

The previous prime is 818977. The next prime is 818999. The reversal of 818993 is 399818.

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 818993 - 2⁴ = 818977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (818999) 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, 188 + ... + 1293.

It is an arithmetic number, because the mean of its divisors is an integer number (118560).

2⁸¹⁸⁹⁹³ is an apocalyptic number.

It is an amenable number.

818993 is a deficient number, since it is larger than the sum of its proper divisors (129487).

818993 is a wasteful number, since it uses less digits than its factorization.

818993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1567.

The product of its digits is 15552, while the sum is 38.

The square root of 818993 is about 904.9823202693. The cubic root of 818993 is about 93.5606858173.

The spelling of 818993 in words is "eight hundred eighteen thousand, nine hundred ninety-three".