810778600061 has 2 divisors, whose sum is σ = 810778600062. Its totient is φ = 810778600060.

The previous prime is 810778600057. The next prime is 810778600097. The reversal of 810778600061 is 160006877018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 588849043225 + 221929556836 = 767365^2 + 471094^2 .

It is a cyclic number.

It is not a de Polignac number, because 810778600061 - 2² = 810778600057 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 810778599985 and 810778600021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (810778600031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405389300030 + 405389300031.

It is an arithmetic number, because the mean of its divisors is an integer number (405389300031).

Almost surely, 2^810778600061 is an apocalyptic number.

It is an amenable number.

810778600061 is a deficient number, since it is larger than the sum of its proper divisors (1).

810778600061 is an equidigital number, since it uses as much as digits as its factorization.

810778600061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112896, while the sum is 44.

The spelling of 810778600061 in words is "eight hundred ten billion, seven hundred seventy-eight million, six hundred thousand, sixty-one".