201915221 has 2 divisors, whose sum is σ = 201915222. Its totient is φ = 201915220.

The previous prime is 201915209. The next prime is 201915251. The reversal of 201915221 is 122519102.

201915221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 195720100 + 6195121 = 13990^2 + 2489^2 .

It is a cyclic number.

It is not a de Polignac number, because 201915221 - 2⁶ = 201915157 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201915251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100957610 + 100957611.

It is an arithmetic number, because the mean of its divisors is an integer number (100957611).

Almost surely, 2^201915221 is an apocalyptic number.

It is an amenable number.

201915221 is a deficient number, since it is larger than the sum of its proper divisors (1).

201915221 is an equidigital number, since it uses as much as digits as its factorization.

201915221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 201915221 is about 14209.6875757351. The cubic root of 201915221 is about 586.6643339195.

The spelling of 201915221 in words is "two hundred one million, nine hundred fifteen thousand, two hundred twenty-one".