91989573 has 12 divisors (see below), whose sum is σ = 132814080. Its totient is φ = 56608656.

The previous prime is 91989497. The next prime is 91989577. The reversal of 91989573 is 37598919.

It is a happy number.

It is not a de Polignac number, because 91989573 - 2¹⁸ = 91727429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91989577) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 90213 + ... + 91226.

It is an arithmetic number, because the mean of its divisors is an integer number (11067840).

Almost surely, 2^91989573 is an apocalyptic number.

It is an amenable number.

91989573 is a deficient number, since it is larger than the sum of its proper divisors (40824507).

91989573 is a wasteful number, since it uses less digits than its factorization.

91989573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181468 (or 181455 counting only the distinct ones).

The product of its digits is 612360, while the sum is 51.

The square root of 91989573 is about 9591.1194862748. The cubic root of 91989573 is about 451.4186881186.

The spelling of 91989573 in words is "ninety-one million, nine hundred eighty-nine thousand, five hundred seventy-three".