91128543 has 8 divisors (see below), whose sum is σ = 132550656. Its totient is φ = 55229400.

The previous prime is 91128523. The next prime is 91128577. The reversal of 91128543 is 34582119.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91128543 - 2¹² = 91124447 is a prime.

It is a super-2 number, since 2×91128543² = 16608822698605698, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 2761471 = 91128543 / (9 + 1 + 1 + 2 + 8 + 5 + 4 + 3).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91128523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1380703 + ... + 1380768.

It is an arithmetic number, because the mean of its divisors is an integer number (16568832).

Almost surely, 2^91128543 is an apocalyptic number.

91128543 is a deficient number, since it is larger than the sum of its proper divisors (41422113).

91128543 is a wasteful number, since it uses less digits than its factorization.

91128543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2761485.

The product of its digits is 8640, while the sum is 33.

The square root of 91128543 is about 9546.1271204609. The cubic root of 91128543 is about 450.0058320232.

The spelling of 91128543 in words is "ninety-one million, one hundred twenty-eight thousand, five hundred forty-three".