820655737877 has 2 divisors, whose sum is σ = 820655737878. Its totient is φ = 820655737876.

The previous prime is 820655737789. The next prime is 820655737903. The reversal of 820655737877 is 778737556028.

820655737877 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 772727144401 + 47928593476 = 879049^2 + 218926^2 .

It is a cyclic number.

It is not a de Polignac number, because 820655737877 - 2³⁰ = 819581996053 is a prime.

It is a super-2 number, since 2×820655737877² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (820655737177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410327868938 + 410327868939.

It is an arithmetic number, because the mean of its divisors is an integer number (410327868939).

Almost surely, 2^820655737877 is an apocalyptic number.

It is an amenable number.

820655737877 is a deficient number, since it is larger than the sum of its proper divisors (1).

820655737877 is an equidigital number, since it uses as much as digits as its factorization.

820655737877 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 138297600, while the sum is 65.

The spelling of 820655737877 in words is "eight hundred twenty billion, six hundred fifty-five million, seven hundred thirty-seven thousand, eight hundred seventy-seven".