9001661 has 4 divisors (see below), whose sum is σ = 9011424. Its totient is φ = 8991900.

The previous prime is 9001627. The next prime is 9001667. The reversal of 9001661 is 1661009.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1661009 = 7 ⋅237287.

It is a cyclic number.

It is not a de Polignac number, because 9001661 - 2¹⁰ = 9000637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9001667) 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 3 ways as a sum of consecutive naturals, for example, 3335 + ... + 5396.

It is an arithmetic number, because the mean of its divisors is an integer number (2252856).

Almost surely, 2^9001661 is an apocalyptic number.

It is an amenable number.

9001661 is a deficient number, since it is larger than the sum of its proper divisors (9763).

9001661 is a wasteful number, since it uses less digits than its factorization.

9001661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9762.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 9001661 is about 3000.2768205617. The cubic root of 9001661 is about 208.0211778856.

The spelling of 9001661 in words is "nine million, one thousand, six hundred sixty-one".