91989025 has 12 divisors (see below), whose sum is σ = 114306300. Its totient is φ = 73436480.

The previous prime is 91989019. The next prime is 91989103. The reversal of 91989025 is 52098919.

It can be written as a sum of positive squares in 6 ways, for example, as 13719616 + 78269409 = 3704^2 + 8847^2 .

It is a de Polignac number, because none of the positive numbers 2^k-91989025 is a prime.

It is an unprimeable number.

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 in 11 ways as a sum of consecutive naturals, for example, 9111 + ... + 16339.

It is an arithmetic number, because the mean of its divisors is an integer number (9525525).

Almost surely, 2^91989025 is an apocalyptic number.

It is an amenable number.

91989025 is a deficient number, since it is larger than the sum of its proper divisors (22317275).

91989025 is a wasteful number, since it uses less digits than its factorization.

91989025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7748 (or 7743 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 43.

The square root of 91989025 is about 9591.0909181386. The cubic root of 91989025 is about 451.4177917202.

The spelling of 91989025 in words is "ninety-one million, nine hundred eighty-nine thousand, twenty-five".