820618905577 has 2 divisors, whose sum is σ = 820618905578. Its totient is φ = 820618905576.

The previous prime is 820618905551. The next prime is 820618905607. The reversal of 820618905577 is 775509816028.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 606235089321 + 214383816256 = 778611^2 + 463016^2 .

It is a cyclic number.

It is not a de Polignac number, because 820618905577 - 2²⁷ = 820484687849 is a prime.

It is a super-3 number, since 3×820618905577³ (a number of 37 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (820618905077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410309452788 + 410309452789.

It is an arithmetic number, because the mean of its divisors is an integer number (410309452789).

Almost surely, 2^820618905577 is an apocalyptic number.

It is an amenable number.

820618905577 is a deficient number, since it is larger than the sum of its proper divisors (1).

820618905577 is an equidigital number, since it uses as much as digits as its factorization.

820618905577 is an evil number, because the sum of its binary digits is even.

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

The spelling of 820618905577 in words is "eight hundred twenty billion, six hundred eighteen million, nine hundred five thousand, five hundred seventy-seven".