999899851 has 2 divisors, whose sum is σ = 999899852. Its totient is φ = 999899850.

The previous prime is 999899821. The next prime is 999899867. The reversal of 999899851 is 158998999.

It is a strong prime.

It is an emirp because it is prime and its reverse (158998999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999899851 - 2⁵ = 999899819 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (999899801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499949925 + 499949926.

It is an arithmetic number, because the mean of its divisors is an integer number (499949926).

Almost surely, 2^999899851 is an apocalyptic number.

999899851 is a deficient number, since it is larger than the sum of its proper divisors (1).

999899851 is an equidigital number, since it uses as much as digits as its factorization.

999899851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18895680, while the sum is 67.

The square root of 999899851 is about 31621.1930673085. The cubic root of 999899851 is about 999.9666158855.

The spelling of 999899851 in words is "nine hundred ninety-nine million, eight hundred ninety-nine thousand, eight hundred fifty-one".