91866819 has 16 divisors (see below), whose sum is σ = 137237760. Its totient is φ = 54171360.

The previous prime is 91866799. The next prime is 91866851.

91866819 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 91866819 - 2⁵ = 91866787 is a prime.

It is a super-2 number, since 2×91866819² = 16879024866357522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91866319) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36399 + ... + 38840.

It is an arithmetic number, because the mean of its divisors is an integer number (8577360).

Almost surely, 2^91866819 is an apocalyptic number.

91866819 is a deficient number, since it is larger than the sum of its proper divisors (45370941).

91866819 is a wasteful number, since it uses less digits than its factorization.

91866819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75290.

The product of its digits is 186624, while the sum is 48.

The square root of 91866819 is about 9584.7179927215. The cubic root of 91866819 is about 451.2178026101.

The spelling of 91866819 in words is "ninety-one million, eight hundred sixty-six thousand, eight hundred nineteen".