201516221 has 2 divisors, whose sum is σ = 201516222. Its totient is φ = 201516220.

The previous prime is 201516199. The next prime is 201516233. The reversal of 201516221 is 122615102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171976996 + 29539225 = 13114^2 + 5435^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201516221 is a prime.

It is a super-2 number, since 2×201516221² = 81217574652241682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 201516193 and 201516202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (203516221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100758110 + 100758111.

It is an arithmetic number, because the mean of its divisors is an integer number (100758111).

Almost surely, 2^201516221 is an apocalyptic number.

It is an amenable number.

201516221 is a deficient number, since it is larger than the sum of its proper divisors (1).

201516221 is an equidigital number, since it uses as much as digits as its factorization.

201516221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 201516221 is about 14195.6409154360. The cubic root of 201516221 is about 586.2776478248.

The spelling of 201516221 in words is "two hundred one million, five hundred sixteen thousand, two hundred twenty-one".