91487447 has 4 divisors (see below), whose sum is σ = 91642320. Its totient is φ = 91332576.

The previous prime is 91487419. The next prime is 91487449. The reversal of 91487447 is 74478419.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74478419 = 769 ⋅96851.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91487447 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91487398 and 91487407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91487449) 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, 76547 + ... + 77732.

It is an arithmetic number, because the mean of its divisors is an integer number (22910580).

Almost surely, 2^91487447 is an apocalyptic number.

91487447 is a deficient number, since it is larger than the sum of its proper divisors (154873).

91487447 is a wasteful number, since it uses less digits than its factorization.

91487447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154872.

The product of its digits is 225792, while the sum is 44.

The square root of 91487447 is about 9564.9070565270. The cubic root of 91487447 is about 450.5958313058.

Subtracting from 91487447 its reverse (74478419), we obtain a triangular number (17009028 = T₅₈₃₂).

The spelling of 91487447 in words is "ninety-one million, four hundred eighty-seven thousand, four hundred forty-seven".