9090907891 has 4 divisors (see below), whose sum is σ = 9790208512. Its totient is φ = 8391607272.

The previous prime is 9090907873. The next prime is 9090907919. The reversal of 9090907891 is 1987090909.

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 9090907891 - 2¹⁷ = 9090776819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9090907391) 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, 349650291 + ... + 349650316.

It is an arithmetic number, because the mean of its divisors is an integer number (2447552128).

Almost surely, 2^9090907891 is an apocalyptic number.

9090907891 is a deficient number, since it is larger than the sum of its proper divisors (699300621).

9090907891 is a wasteful number, since it uses less digits than its factorization.

9090907891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699300620.

The product of its (nonzero) digits is 367416, while the sum is 52.

The square root of 9090907891 is about 95346.2526321827. The cubic root of 9090907891 is about 2087.0639305994.

The spelling of 9090907891 in words is "nine billion, ninety million, nine hundred seven thousand, eight hundred ninety-one".