200109781 has 2 divisors, whose sum is σ = 200109782. Its totient is φ = 200109780.

The previous prime is 200109757. The next prime is 200109797. The reversal of 200109781 is 187901002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 177156100 + 22953681 = 13310^2 + 4791^2 .

It is a cyclic number.

It is not a de Polignac number, because 200109781 - 2²⁷ = 65892053 is a prime.

It is a super-2 number, since 2×200109781² = 80087848903735922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (200109751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100054890 + 100054891.

It is an arithmetic number, because the mean of its divisors is an integer number (100054891).

Almost surely, 2^200109781 is an apocalyptic number.

It is an amenable number.

200109781 is a deficient number, since it is larger than the sum of its proper divisors (1).

200109781 is an equidigital number, since it uses as much as digits as its factorization.

200109781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 200109781 is about 14146.0164357320. The cubic root of 200109781 is about 584.9105286013.

It can be divided in two parts, 20010 and 9781, that added together give a cube (29791 = 31³).

The spelling of 200109781 in words is "two hundred million, one hundred nine thousand, seven hundred eighty-one".