919191091 has 16 divisors (see below), whose sum is σ = 1157626624. Its totient is φ = 710355744.

The previous prime is 919191043. The next prime is 919191151. The reversal of 919191091 is 190191919.

It is not a de Polignac number, because 919191091 - 2¹⁷ = 919060019 is a prime.

It is not an unprimeable number, because it can be changed into a prime (919191011) 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, 113541 + ... + 121366.

It is an arithmetic number, because the mean of its divisors is an integer number (72351664).

Almost surely, 2^919191091 is an apocalyptic number.

919191091 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

919191091 is a deficient number, since it is larger than the sum of its proper divisors (238435533).

919191091 is a wasteful number, since it uses less digits than its factorization.

919191091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234970.

The product of its (nonzero) digits is 6561, while the sum is 40.

The square root of 919191091 is about 30318.1643738535. The cubic root of 919191091 is about 972.3036934122.

The spelling of 919191091 in words is "nine hundred nineteen million, one hundred ninety-one thousand, ninety-one".