9201221 has 2 divisors, whose sum is σ = 9201222. Its totient is φ = 9201220.

The previous prime is 9201217. The next prime is 9201253. The reversal of 9201221 is 1221029.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8940100 + 261121 = 2990^2 + 511^2 .

It is an emirp because it is prime and its reverse (1221029) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9201221 - 2² = 9201217 is a prime.

It is a Chen prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 9201221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9201211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4600610 + 4600611.

It is an arithmetic number, because the mean of its divisors is an integer number (4600611).

Almost surely, 2^9201221 is an apocalyptic number.

It is an amenable number.

9201221 is a deficient number, since it is larger than the sum of its proper divisors (1).

9201221 is an equidigital number, since it uses as much as digits as its factorization.

9201221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 9201221 is about 3033.3514468324. The cubic root of 9201221 is about 209.5471799992.

The spelling of 9201221 in words is "nine million, two hundred one thousand, two hundred twenty-one".