91566973 has 4 divisors (see below), whose sum is σ = 91587100. Its totient is φ = 91546848.

The previous prime is 91566967. The next prime is 91566977. The reversal of 91566973 is 37966519.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 70526404 + 21040569 = 8398^2 + 4587^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91566973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91566977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 361 + ... + 13537.

It is an arithmetic number, because the mean of its divisors is an integer number (22896775).

Almost surely, 2^91566973 is an apocalyptic number.

It is an amenable number.

91566973 is a deficient number, since it is larger than the sum of its proper divisors (20127).

91566973 is a wasteful number, since it uses less digits than its factorization.

91566973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20126.

The product of its digits is 306180, while the sum is 46.

The square root of 91566973 is about 9569.0633292920. The cubic root of 91566973 is about 450.7263545170.

It can be divided in two parts, 9156 and 6973, that added together give a square (16129 = 127²).

The spelling of 91566973 in words is "ninety-one million, five hundred sixty-six thousand, nine hundred seventy-three".