9901001 has 4 divisors (see below), whose sum is σ = 10801104. Its totient is φ = 9000900.

The previous prime is 9900959. The next prime is 9901007. The reversal of 9901001 is 1001099.

9901001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1001099 = 11 ⋅91009.

It is a cyclic number.

It is not a de Polignac number, because 9901001 - 2¹⁰ = 9899977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9901007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 450035 + ... + 450056.

It is an arithmetic number, because the mean of its divisors is an integer number (2700276).

Almost surely, 2^9901001 is an apocalyptic number.

It is an amenable number.

9901001 is a deficient number, since it is larger than the sum of its proper divisors (900103).

9901001 is a wasteful number, since it uses less digits than its factorization.

9901001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900102.

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

The square root of 9901001 is about 3146.5856098317. The cubic root of 9901001 is about 214.7301536156.

It can be divided in two parts, 990 and 1001, that added together give a palindrome (1991).

The spelling of 9901001 in words is "nine million, nine hundred one thousand, one".