6820201781 has 2 divisors, whose sum is σ = 6820201782. Its totient is φ = 6820201780.

The previous prime is 6820201771. The next prime is 6820201811. The reversal of 6820201781 is 1871020286.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6594901681 + 225300100 = 81209^2 + 15010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6820201781 is a prime.

It is a super-2 number, since 2×6820201781² = 93030304667111143922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6820201711) 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, 3410100890 + 3410100891.

It is an arithmetic number, because the mean of its divisors is an integer number (3410100891).

Almost surely, 2^6820201781 is an apocalyptic number.

It is an amenable number.

6820201781 is a deficient number, since it is larger than the sum of its proper divisors (1).

6820201781 is an equidigital number, since it uses as much as digits as its factorization.

6820201781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 6820201781 is about 82584.5129609662. The cubic root of 6820201781 is about 1896.4107475216.

The spelling of 6820201781 in words is "six billion, eight hundred twenty million, two hundred one thousand, seven hundred eighty-one".