91299791 has 4 divisors (see below), whose sum is σ = 99599784. Its totient is φ = 82999800.

The previous prime is 91299779. The next prime is 91299799. The reversal of 91299791 is 19799219.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19799219 = 11 ⋅1799929.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91299791 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91299799) 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 3 ways as a sum of consecutive naturals, for example, 4149980 + ... + 4150001.

It is an arithmetic number, because the mean of its divisors is an integer number (24899946).

Almost surely, 2^91299791 is an apocalyptic number.

91299791 is a deficient number, since it is larger than the sum of its proper divisors (8299993).

91299791 is a wasteful number, since it uses less digits than its factorization.

91299791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8299992.

The product of its digits is 91854, while the sum is 47.

The square root of 91299791 is about 9555.0924119027. The cubic root of 91299791 is about 450.2875380424.

The spelling of 91299791 in words is "ninety-one million, two hundred ninety-nine thousand, seven hundred ninety-one".