989894987 has 2 divisors, whose sum is σ = 989894988. Its totient is φ = 989894986.

The previous prime is 989894981. The next prime is 989895013. The reversal of 989894987 is 789498989.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-989894987 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 989894987.

It is not a weakly prime, because it can be changed into another prime (989894981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494947493 + 494947494.

It is an arithmetic number, because the mean of its divisors is an integer number (494947494).

Almost surely, 2^989894987 is an apocalyptic number.

989894987 is a deficient number, since it is larger than the sum of its proper divisors (1).

989894987 is an equidigital number, since it uses as much as digits as its factorization.

989894987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 94058496, while the sum is 71.

The square root of 989894987 is about 31462.5966347344. The cubic root of 989894987 is about 996.6202525088.

The spelling of 989894987 in words is "nine hundred eighty-nine million, eight hundred ninety-four thousand, nine hundred eighty-seven".