999359891 has 16 divisors (see below), whose sum is σ = 1077408000. Its totient is φ = 924045408.

The previous prime is 999359857. The next prime is 999359939. The reversal of 999359891 is 198953999.

It is a cyclic number.

It is not a de Polignac number, because 999359891 - 2¹⁸ = 999097747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (999359791) 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, 197900 + ... + 202886.

It is an arithmetic number, because the mean of its divisors is an integer number (67338000).

Almost surely, 2^999359891 is an apocalyptic number.

999359891 is a deficient number, since it is larger than the sum of its proper divisors (78048109).

999359891 is a wasteful number, since it uses less digits than its factorization.

999359891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5258.

The product of its digits is 7085880, while the sum is 62.

The square root of 999359891 is about 31612.6539695736. The cubic root of 999359891 is about 999.7865847905.

The spelling of 999359891 in words is "nine hundred ninety-nine million, three hundred fifty-nine thousand, eight hundred ninety-one".