91215243 has 12 divisors (see below), whose sum is σ = 150577648. Its totient is φ = 52122960.

The previous prime is 91215209. The next prime is 91215287. The reversal of 91215243 is 34251219.

It is not a de Polignac number, because 91215243 - 2¹⁷ = 91084171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91215343) 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 11 ways as a sum of consecutive naturals, for example, 723868 + ... + 723993.

Almost surely, 2^91215243 is an apocalyptic number.

91215243 is a deficient number, since it is larger than the sum of its proper divisors (59362405).

91215243 is a wasteful number, since it uses less digits than its factorization.

91215243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1447874 (or 1447871 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 91215243 is about 9550.6671494718. The cubic root of 91215243 is about 450.1484991383.

The spelling of 91215243 in words is "ninety-one million, two hundred fifteen thousand, two hundred forty-three".