91281545 has 4 divisors (see below), whose sum is σ = 109537860. Its totient is φ = 73025232.

The previous prime is 91281523. The next prime is 91281557. The reversal of 91281545 is 54518219.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54518219 = 7 ⋅7788317.

It can be written as a sum of positive squares in 2 ways, for example, as 70341769 + 20939776 = 8387^2 + 4576^2 .

It is a cyclic number.

It is not a de Polignac number, because 91281545 - 2¹⁰ = 91280521 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9128150 + ... + 9128159.

It is an arithmetic number, because the mean of its divisors is an integer number (27384465).

Almost surely, 2^91281545 is an apocalyptic number.

It is an amenable number.

91281545 is a deficient number, since it is larger than the sum of its proper divisors (18256315).

91281545 is a wasteful number, since it uses less digits than its factorization.

91281545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18256314.

The product of its digits is 14400, while the sum is 35.

The square root of 91281545 is about 9554.1375853606. The cubic root of 91281545 is about 450.2575398219.

The spelling of 91281545 in words is "ninety-one million, two hundred eighty-one thousand, five hundred forty-five".