9921990417 has 32 divisors (see below), whose sum is σ = 13828254720. Its totient is φ = 6320885760.

The previous prime is 9921990391. The next prime is 9921990431. The reversal of 9921990417 is 7140991299.

9921990417 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9921990417 - 2⁷ = 9921990289 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9921990417.

It is not an unprimeable number, because it can be changed into a prime (9921990497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5131983 + ... + 5133915.

It is an arithmetic number, because the mean of its divisors is an integer number (432132960).

Almost surely, 2^9921990417 is an apocalyptic number.

9921990417 is a gapful number since it is divisible by the number (97) formed by its first and last digit.

It is an amenable number.

9921990417 is a deficient number, since it is larger than the sum of its proper divisors (3906264303).

9921990417 is a wasteful number, since it uses less digits than its factorization.

9921990417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2633.

The product of its (nonzero) digits is 367416, while the sum is 51.

The square root of 9921990417 is about 99609.1884165311. The cubic root of 9921990417 is about 2148.8178406181.

The spelling of 9921990417 in words is "nine billion, nine hundred twenty-one million, nine hundred ninety thousand, four hundred seventeen".