91161805 has 24 divisors (see below), whose sum is σ = 128816352. Its totient is φ = 61744032.

The previous prime is 91161781. The next prime is 91161809. The reversal of 91161805 is 50816119.

It is not a de Polignac number, because 91161805 - 2⁵ = 91161773 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91161809) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18094 + ... + 22576.

It is an arithmetic number, because the mean of its divisors is an integer number (5367348).

Almost surely, 2^91161805 is an apocalyptic number.

It is an amenable number.

91161805 is a deficient number, since it is larger than the sum of its proper divisors (37654547).

91161805 is a wasteful number, since it uses less digits than its factorization.

91161805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4585 (or 4578 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 31.

The square root of 91161805 is about 9547.8691340005. The cubic root of 91161805 is about 450.0605762074.

The spelling of 91161805 in words is "ninety-one million, one hundred sixty-one thousand, eight hundred five".