91004989 has 2 divisors, whose sum is σ = 91004990. Its totient is φ = 91004988.

The previous prime is 91004983. The next prime is 91004993. The reversal of 91004989 is 98940019.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79512889 + 11492100 = 8917^2 + 3390^2 .

It is a cyclic number.

It is not a de Polignac number, because 91004989 - 2⁵ = 91004957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91004983) 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, 45502494 + 45502495.

It is an arithmetic number, because the mean of its divisors is an integer number (45502495).

Almost surely, 2^91004989 is an apocalyptic number.

It is an amenable number.

91004989 is a deficient number, since it is larger than the sum of its proper divisors (1).

91004989 is an equidigital number, since it uses as much as digits as its factorization.

91004989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 91004989 is about 9539.6535052380. The cubic root of 91004989 is about 449.8023642418.

The spelling of 91004989 in words is "ninety-one million, four thousand, nine hundred eighty-nine".