91389081 has 16 divisors (see below), whose sum is σ = 139797504. Its totient is φ = 52020624.

The previous prime is 91389079. The next prime is 91389083. The reversal of 91389081 is 18098319.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (91389079) and next prime (91389083).

It is not a de Polignac number, because 91389081 - 2¹ = 91389079 is a prime.

It is a super-2 number, since 2×91389081² = 16703928252049122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91389083) 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, 2751 + ... + 13796.

It is an arithmetic number, because the mean of its divisors is an integer number (8737344).

Almost surely, 2^91389081 is an apocalyptic number.

It is an amenable number.

91389081 is a deficient number, since it is larger than the sum of its proper divisors (48408423).

91389081 is a wasteful number, since it uses less digits than its factorization.

91389081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16820.

The product of its (nonzero) digits is 15552, while the sum is 39.

The square root of 91389081 is about 9559.7636477059. The cubic root of 91389081 is about 450.4342819868.

The spelling of 91389081 in words is "ninety-one million, three hundred eighty-nine thousand, eighty-one".