200818561 has 2 divisors, whose sum is σ = 200818562. Its totient is φ = 200818560.

The previous prime is 200818559. The next prime is 200818567. The reversal of 200818561 is 165818002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163840000 + 36978561 = 12800^2 + 6081^2 .

It is a cyclic number.

It is not a de Polignac number, because 200818561 - 2¹ = 200818559 is a prime.

It is a super-2 number, since 2×200818561² = 80656188884221442, which contains 22 as substring.

Together with 200818559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (200818567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100409280 + 100409281.

It is an arithmetic number, because the mean of its divisors is an integer number (100409281).

Almost surely, 2^200818561 is an apocalyptic number.

It is an amenable number.

200818561 is a deficient number, since it is larger than the sum of its proper divisors (1).

200818561 is an equidigital number, since it uses as much as digits as its factorization.

200818561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 200818561 is about 14171.0465739126. The cubic root of 200818561 is about 585.6002906192.

The spelling of 200818561 in words is "two hundred million, eight hundred eighteen thousand, five hundred sixty-one".