91199389 has 2 divisors, whose sum is σ = 91199390. Its totient is φ = 91199388.

The previous prime is 91199371. The next prime is 91199419. The reversal of 91199389 is 98399119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77264100 + 13935289 = 8790^2 + 3733^2 .

It is a cyclic number.

It is not a de Polignac number, because 91199389 - 2⁵ = 91199357 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91199089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45599694 + 45599695.

It is an arithmetic number, because the mean of its divisors is an integer number (45599695).

Almost surely, 2^91199389 is an apocalyptic number.

It is an amenable number.

91199389 is a deficient number, since it is larger than the sum of its proper divisors (1).

91199389 is an equidigital number, since it uses as much as digits as its factorization.

91199389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157464, while the sum is 49.

The square root of 91199389 is about 9549.8371190298. The cubic root of 91199389 is about 450.1224177233.

The spelling of 91199389 in words is "ninety-one million, one hundred ninety-nine thousand, three hundred eighty-nine".