91208947 has 4 divisors (see below), whose sum is σ = 91533816. Its totient is φ = 90884080.

The previous prime is 91208941. The next prime is 91209059. The reversal of 91208947 is 74980219.

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

It is a cyclic number.

It is not a de Polignac number, because 91208947 - 2³ = 91208939 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91208941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 162013 + ... + 162574.

It is an arithmetic number, because the mean of its divisors is an integer number (22883454).

Almost surely, 2^91208947 is an apocalyptic number.

91208947 is a deficient number, since it is larger than the sum of its proper divisors (324869).

91208947 is a wasteful number, since it uses less digits than its factorization.

91208947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324868.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 91208947 is about 9550.3375333022. The cubic root of 91208947 is about 450.1381419507.

The spelling of 91208947 in words is "ninety-one million, two hundred eight thousand, nine hundred forty-seven".