201242221 has 2 divisors, whose sum is σ = 201242222. Its totient is φ = 201242220.

The previous prime is 201242207. The next prime is 201242257. The reversal of 201242221 is 122242102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199515625 + 1726596 = 14125^2 + 1314^2 .

It is a cyclic number.

It is not a de Polignac number, because 201242221 - 2⁵ = 201242189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 201242195 and 201242204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201242291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100621110 + 100621111.

It is an arithmetic number, because the mean of its divisors is an integer number (100621111).

Almost surely, 2^201242221 is an apocalyptic number.

It is an amenable number.

201242221 is a deficient number, since it is larger than the sum of its proper divisors (1).

201242221 is an equidigital number, since it uses as much as digits as its factorization.

201242221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 201242221 is about 14185.9867827374. The cubic root of 201242221 is about 586.0118082863.

Adding to 201242221 its reverse (122242102), we get a palindrome (323484323).

The spelling of 201242221 in words is "two hundred one million, two hundred forty-two thousand, two hundred twenty-one".