9901001000 has 64 divisors (see below), whose sum is σ = 25274583360. Its totient is φ = 3600360000.

The previous prime is 9901000961. The next prime is 9901001009. The reversal of 9901001000 is 1001099.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (9901001009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 439046 + ... + 461045.

It is an arithmetic number, because the mean of its divisors is an integer number (394915365).

Almost surely, 2^9901001000 is an apocalyptic number.

It is an amenable number.

9901001000 is an abundant number, since it is smaller than the sum of its proper divisors (15373582360).

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

9901001000 is a wasteful number, since it uses less digits than its factorization.

9901001000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 900123 (or 900109 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 20.

The square root of 9901001000 is about 99503.7737977812. The cubic root of 9901001000 is about 2147.3015361557.

Adding to 9901001000 its reverse (1001099), we get a palindrome (9902002099).

The spelling of 9901001000 in words is "nine billion, nine hundred one million, one thousand".