9899623656 has 384 divisors, whose sum is σ = 32196528000. Its totient is φ = 2823994368.

The previous prime is 9899623639. The next prime is 9899623667. The reversal of 9899623656 is 6563269989.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 9899623593 and 9899623602.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 25448710 + ... + 25449098.

It is an arithmetic number, because the mean of its divisors is an integer number (83845125).

Almost surely, 2^9899623656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9899623656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16098264000).

9899623656 is an abundant number, since it is smaller than the sum of its proper divisors (22296904344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9899623656 is a wasteful number, since it uses less digits than its factorization.

9899623656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495 (or 479 counting only the distinct ones).

The product of its digits is 37791360, while the sum is 63.

The square root of 9899623656 is about 99496.8524929306. The cubic root of 9899623656 is about 2147.2019600272.

The spelling of 9899623656 in words is "nine billion, eight hundred ninety-nine million, six hundred twenty-three thousand, six hundred fifty-six".