201056561 has 2 divisors, whose sum is σ = 201056562. Its totient is φ = 201056560.

The previous prime is 201056539. The next prime is 201056563. The reversal of 201056561 is 165650102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 200392336 + 664225 = 14156^2 + 815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201056561 is a prime.

It is a super-2 number, since 2×201056561² = 80847481442293442, which contains 22 as substring.

Together with 201056563, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 201056561.

It is not a weakly prime, because it can be changed into another prime (201056563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100528280 + 100528281.

It is an arithmetic number, because the mean of its divisors is an integer number (100528281).

Almost surely, 2^201056561 is an apocalyptic number.

It is an amenable number.

201056561 is a deficient number, since it is larger than the sum of its proper divisors (1).

201056561 is an equidigital number, since it uses as much as digits as its factorization.

201056561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 201056561 is about 14179.4414911166. The cubic root of 201056561 is about 585.8315405686.

The spelling of 201056561 in words is "two hundred one million, fifty-six thousand, five hundred sixty-one".