201221857 has 2 divisors, whose sum is σ = 201221858. Its totient is φ = 201221856.

The previous prime is 201221849. The next prime is 201221861. The reversal of 201221857 is 758122102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 180391761 + 20830096 = 13431^2 + 4564^2 .

It is a cyclic number.

It is not a de Polignac number, because 201221857 - 2³ = 201221849 is a prime.

It is not a weakly prime, because it can be changed into another prime (201221827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100610928 + 100610929.

It is an arithmetic number, because the mean of its divisors is an integer number (100610929).

Almost surely, 2^201221857 is an apocalyptic number.

It is an amenable number.

201221857 is a deficient number, since it is larger than the sum of its proper divisors (1).

201221857 is an equidigital number, since it uses as much as digits as its factorization.

201221857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 201221857 is about 14185.2690140159. The cubic root of 201221857 is about 585.9920411504.

Adding to 201221857 its reverse (758122102), we get a palindrome (959343959).

The spelling of 201221857 in words is "two hundred one million, two hundred twenty-one thousand, eight hundred fifty-seven".