999220993 has 16 divisors (see below), whose sum is σ = 1059379200. Its totient is φ = 940539600.

The previous prime is 999220973. The next prime is 999221009. The reversal of 999220993 is 399022999.

It is a cyclic number.

It is not a de Polignac number, because 999220993 - 2⁵ = 999220961 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 999220993.

It is not an unprimeable number, because it can be changed into a prime (999220933) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 687918 + ... + 689368.

It is an arithmetic number, because the mean of its divisors is an integer number (66211200).

Almost surely, 2^999220993 is an apocalyptic number.

999220993 is the 16897-th centered heptagonal number.

It is an amenable number.

999220993 is a deficient number, since it is larger than the sum of its proper divisors (60158207).

999220993 is a wasteful number, since it uses less digits than its factorization.

999220993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1932.

The product of its (nonzero) digits is 708588, while the sum is 52.

The square root of 999220993 is about 31610.4570197901. The cubic root of 999220993 is about 999.7402635428.

The spelling of 999220993 in words is "nine hundred ninety-nine million, two hundred twenty thousand, nine hundred ninety-three".