9991921033 has 2 divisors, whose sum is σ = 9991921034. Its totient is φ = 9991921032.

The previous prime is 9991920997. The next prime is 9991921061. The reversal of 9991921033 is 3301291999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6562296064 + 3429624969 = 81008^2 + 58563^2 .

It is a cyclic number.

It is not a de Polignac number, because 9991921033 - 2³³ = 1401986441 is a prime.

It is not a weakly prime, because it can be changed into another prime (9991921133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995960516 + 4995960517.

It is an arithmetic number, because the mean of its divisors is an integer number (4995960517).

Almost surely, 2^9991921033 is an apocalyptic number.

It is an amenable number.

9991921033 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991921033 is an equidigital number, since it uses as much as digits as its factorization.

9991921033 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 118098, while the sum is 46.

The square root of 9991921033 is about 99959.5970029892. The cubic root of 9991921033 is about 2153.8543468259.

The spelling of 9991921033 in words is "nine billion, nine hundred ninety-one million, nine hundred twenty-one thousand, thirty-three".