9991090901 has 8 divisors (see below), whose sum is σ = 10903093344. Its totient is φ = 9079708720.

The previous prime is 9991090877. The next prime is 9991090919. The reversal of 9991090901 is 1090901999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9991090901 - 2²² = 9986896597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9991090931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121055 + ... + 186108.

It is an arithmetic number, because the mean of its divisors is an integer number (1362886668).

Almost surely, 2^9991090901 is an apocalyptic number.

It is an amenable number.

9991090901 is a deficient number, since it is larger than the sum of its proper divisors (912002443).

9991090901 is a wasteful number, since it uses less digits than its factorization.

9991090901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310131.

The product of its (nonzero) digits is 59049, while the sum is 47.

The square root of 9991090901 is about 99955.4445790723. Note that the first 3 decimals coincide. The cubic root of 9991090901 is about 2153.7946975376.

The spelling of 9991090901 in words is "nine billion, nine hundred ninety-one million, ninety thousand, nine hundred one".