999887321 has 4 divisors (see below), whose sum is σ = 1011122100. Its totient is φ = 988652544.

The previous prime is 999887311. The next prime is 999887323. The reversal of 999887321 is 123788999.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 345550921 + 654336400 = 18589^2 + 25580^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999887321 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (999887323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5617256 + ... + 5617433.

It is an arithmetic number, because the mean of its divisors is an integer number (252780525).

Almost surely, 2^999887321 is an apocalyptic number.

It is an amenable number.

999887321 is a deficient number, since it is larger than the sum of its proper divisors (11234779).

999887321 is a wasteful number, since it uses less digits than its factorization.

999887321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11234778.

The product of its digits is 1959552, while the sum is 56.

The square root of 999887321 is about 31620.9949400711. The cubic root of 999887321 is about 999.9624389225.

The spelling of 999887321 in words is "nine hundred ninety-nine million, eight hundred eighty-seven thousand, three hundred twenty-one".