9900991560 has 64 divisors (see below), whose sum is σ = 29710514880. Its totient is φ = 2639594240.

The previous prime is 9900991543. The next prime is 9900991567. The reversal of 9900991560 is 651990099.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (9900991567) 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, 623479 + ... + 639161.

It is an arithmetic number, because the mean of its divisors is an integer number (464226795).

Almost surely, 2^9900991560 is an apocalyptic number.

It is an amenable number.

9900991560 is an abundant number, since it is smaller than the sum of its proper divisors (19809523320).

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

9900991560 is a wasteful number, since it uses less digits than its factorization.

9900991560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20958 (or 20954 counting only the distinct ones).

The product of its (nonzero) digits is 196830, while the sum is 48.

The square root of 9900991560 is about 99503.7263623830. The cubic root of 9900991560 is about 2147.3008537151.

The spelling of 9900991560 in words is "nine billion, nine hundred million, nine hundred ninety-one thousand, five hundred sixty".