999797987 has 2 divisors, whose sum is σ = 999797988. Its totient is φ = 999797986.

The previous prime is 999797947. The next prime is 999798001. The reversal of 999797987 is 789797999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999797987 - 2⁸ = 999797731 is a prime.

It is not a weakly prime, because it can be changed into another prime (999797927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499898993 + 499898994.

It is an arithmetic number, because the mean of its divisors is an integer number (499898994).

Almost surely, 2^999797987 is an apocalyptic number.

999797987 is a deficient number, since it is larger than the sum of its proper divisors (1).

999797987 is an equidigital number, since it uses as much as digits as its factorization.

999797987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 162030456, while the sum is 74.

The square root of 999797987 is about 31619.5823343699. The cubic root of 999797987 is about 999.9326577985.

The spelling of 999797987 in words is "nine hundred ninety-nine million, seven hundred ninety-seven thousand, nine hundred eighty-seven".