816993 has 8 divisors (see below), whose sum is σ = 1210400. Its totient is φ = 544644.

The previous prime is 816971. The next prime is 817013. The reversal of 816993 is 399618.

It is not a de Polignac number, because 816993 - 2⁵ = 816961 is a prime.

It is a Duffinian number.

It is a Curzon number.

816993 is a lucky number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (816593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15103 + ... + 15156.

It is an arithmetic number, because the mean of its divisors is an integer number (151300).

2⁸¹⁶⁹⁹³ is an apocalyptic number.

It is an amenable number.

816993 is a deficient number, since it is larger than the sum of its proper divisors (393407).

816993 is a wasteful number, since it uses less digits than its factorization.

816993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30268 (or 30262 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 816993 is about 903.8766508767. The cubic root of 816993 is about 93.4844646136.

The spelling of 816993 in words is "eight hundred sixteen thousand, nine hundred ninety-three".