9975221 has 4 divisors (see below), whose sum is σ = 9996192. Its totient is φ = 9954252.

The previous prime is 9975197. The next prime is 9975223. The reversal of 9975221 is 1225799.

9975221 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: 1225799 = 461 ⋅2659.

It is a cyclic number.

It is not a de Polignac number, because 9975221 - 2⁶ = 9975157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9975223) 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, 9755 + ... + 10728.

It is an arithmetic number, because the mean of its divisors is an integer number (2499048).

Almost surely, 2^9975221 is an apocalyptic number.

It is an amenable number.

9975221 is a deficient number, since it is larger than the sum of its proper divisors (20971).

9975221 is a wasteful number, since it uses less digits than its factorization.

9975221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20970.

The product of its digits is 11340, while the sum is 35.

The square root of 9975221 is about 3158.3573262061. The cubic root of 9975221 is about 215.2653726965.

The spelling of 9975221 in words is "nine million, nine hundred seventy-five thousand, two hundred twenty-one".