815773561861 has 2 divisors, whose sum is σ = 815773561862. Its totient is φ = 815773561860.

The previous prime is 815773561847. The next prime is 815773561903. The reversal of 815773561861 is 168165377518.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 727769372836 + 88004189025 = 853094^2 + 296655^2 .

It is a cyclic number.

It is not a de Polignac number, because 815773561861 - 2⁹ = 815773561349 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 815773561796 and 815773561805.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (815773561661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 407886780930 + 407886780931.

It is an arithmetic number, because the mean of its divisors is an integer number (407886780931).

Almost surely, 2^815773561861 is an apocalyptic number.

It is an amenable number.

815773561861 is a deficient number, since it is larger than the sum of its proper divisors (1).

815773561861 is an equidigital number, since it uses as much as digits as its factorization.

815773561861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8467200, while the sum is 58.

The spelling of 815773561861 in words is "eight hundred fifteen billion, seven hundred seventy-three million, five hundred sixty-one thousand, eight hundred sixty-one".