9990909591 has 16 divisors (see below), whose sum is σ = 14405959680. Its totient is φ = 6122521440.

The previous prime is 9990909541. The next prime is 9990909611. The reversal of 9990909591 is 1959090999.

It is not a de Polignac number, because 9990909591 - 2⁹ = 9990909079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9990909541) 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, 526615 + ... + 545256.

It is an arithmetic number, because the mean of its divisors is an integer number (900372480).

Almost surely, 2^9990909591 is an apocalyptic number.

9990909591 is a deficient number, since it is larger than the sum of its proper divisors (4415050089).

9990909591 is a wasteful number, since it uses less digits than its factorization.

9990909591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1072126.

The product of its (nonzero) digits is 2657205, while the sum is 60.

The square root of 9990909591 is about 99954.5376208604. The cubic root of 9990909591 is about 2153.7816690344.

The spelling of 9990909591 in words is "nine billion, nine hundred ninety million, nine hundred nine thousand, five hundred ninety-one".