919090919191 has 4 divisors (see below), whose sum is σ = 928190829384. Its totient is φ = 909991009000.

The previous prime is 919090919101. The next prime is 919090919203. The reversal of 919090919191 is 191919090919.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 919090919191 - 2¹³ = 919090910999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (919090919101) 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, 4549954945 + ... + 4549955146.

It is an arithmetic number, because the mean of its divisors is an integer number (232047707346).

Almost surely, 2^919090919191 is an apocalyptic number.

919090919191 is a deficient number, since it is larger than the sum of its proper divisors (9099910193).

919090919191 is a wasteful number, since it uses less digits than its factorization.

919090919191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9099910192.

The product of its (nonzero) digits is 531441, while the sum is 58.

The spelling of 919090919191 in words is "nine hundred nineteen billion, ninety million, nine hundred nineteen thousand, one hundred ninety-one".