9901556817 has 8 divisors (see below), whose sum is σ = 13249059360. Its totient is φ = 6577546080.

The previous prime is 9901556801. The next prime is 9901556843. The reversal of 9901556817 is 7186551099.

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

It is not a de Polignac number, because 9901556817 - 2⁴ = 9901556801 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9901556817.

It is not an unprimeable number, because it can be changed into a prime (9901556017) 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, 5871967 + ... + 5873652.

It is an arithmetic number, because the mean of its divisors is an integer number (1656132420).

Almost surely, 2^9901556817 is an apocalyptic number.

It is an amenable number.

9901556817 is a deficient number, since it is larger than the sum of its proper divisors (3347502543).

9901556817 is a wasteful number, since it uses less digits than its factorization.

9901556817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11745903.

The product of its (nonzero) digits is 680400, while the sum is 51.

The square root of 9901556817 is about 99506.5667029066. The cubic root of 9901556817 is about 2147.3417167517.

The spelling of 9901556817 in words is "nine billion, nine hundred one million, five hundred fifty-six thousand, eight hundred seventeen".