989010991 has 2 divisors, whose sum is σ = 989010992. Its totient is φ = 989010990.

The previous prime is 989010973. The next prime is 989011007. The reversal of 989010991 is 199010989.

It is a strong prime.

It is an emirp because it is prime and its reverse (199010989) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 989010991 - 2²⁷ = 854793263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (989010931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494505495 + 494505496.

It is an arithmetic number, because the mean of its divisors is an integer number (494505496).

Almost surely, 2^989010991 is an apocalyptic number.

989010991 is a deficient number, since it is larger than the sum of its proper divisors (1).

989010991 is an equidigital number, since it uses as much as digits as its factorization.

989010991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52488, while the sum is 46.

The square root of 989010991 is about 31448.5451332808. The cubic root of 989010991 is about 996.3234968896.

The spelling of 989010991 in words is "nine hundred eighty-nine million, ten thousand, nine hundred ninety-one".