999899987 has 2 divisors, whose sum is σ = 999899988. Its totient is φ = 999899986.

The previous prime is 999899933. The next prime is 999900017. The reversal of 999899987 is 789998999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999899987 - 2⁸ = 999899731 is a prime.

It is not a weakly prime, because it can be changed into another prime (999899587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499949993 + 499949994.

It is an arithmetic number, because the mean of its divisors is an integer number (499949994).

Almost surely, 2^999899987 is an apocalyptic number.

999899987 is a deficient number, since it is larger than the sum of its proper divisors (1).

999899987 is an equidigital number, since it uses as much as digits as its factorization.

999899987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 238085568, while the sum is 77.

The square root of 999899987 is about 31621.1952177649. The cubic root of 999899987 is about 999.9666612219.

The spelling of 999899987 in words is "nine hundred ninety-nine million, eight hundred ninety-nine thousand, nine hundred eighty-seven".