91919089 has 4 divisors (see below), whose sum is σ = 94161060. Its totient is φ = 89677120.

The previous prime is 91919083. The next prime is 91919141. The reversal of 91919089 is 98091919.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98091919 = 2789 ⋅35171.

It can be written as a sum of positive squares in 2 ways, for example, as 42146064 + 49773025 = 6492^2 + 7055^2 .

It is a cyclic number.

It is not a de Polignac number, because 91919089 - 2¹⁷ = 91788017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91919083) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1120924 + ... + 1121005.

It is an arithmetic number, because the mean of its divisors is an integer number (23540265).

Almost surely, 2^91919089 is an apocalyptic number.

It is an amenable number.

91919089 is a deficient number, since it is larger than the sum of its proper divisors (2241971).

91919089 is a wasteful number, since it uses less digits than its factorization.

91919089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2241970.

The product of its (nonzero) digits is 52488, while the sum is 46.

The square root of 91919089 is about 9587.4443414291. Note that the first 3 decimals coincide. The cubic root of 91919089 is about 451.3033637267.

The spelling of 91919089 in words is "ninety-one million, nine hundred nineteen thousand, eighty-nine".