91856447 has 4 divisors (see below), whose sum is σ = 91904136. Its totient is φ = 91808760.

The previous prime is 91856417. The next prime is 91856449. The reversal of 91856447 is 74465819.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74465819 = 479 ⋅155461.

It is a cyclic number.

It is not a de Polignac number, because 91856447 - 2⁶ = 91856383 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91856398 and 91856407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91856449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20828 + ... + 24849.

It is an arithmetic number, because the mean of its divisors is an integer number (22976034).

Almost surely, 2^91856447 is an apocalyptic number.

91856447 is a deficient number, since it is larger than the sum of its proper divisors (47689).

91856447 is a wasteful number, since it uses less digits than its factorization.

91856447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47688.

The product of its digits is 241920, while the sum is 44.

The square root of 91856447 is about 9584.1769077996. The cubic root of 91856447 is about 451.2008207544.

The spelling of 91856447 in words is "ninety-one million, eight hundred fifty-six thousand, four hundred forty-seven".