82566117525821 has 2 divisors, whose sum is σ = 82566117525822. Its totient is φ = 82566117525820.

The previous prime is 82566117525757. The next prime is 82566117525863. The reversal of 82566117525821 is 12852571166528.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49698129096100 + 32867988429721 = 7049690^2 + 5733061^2 .

It is a cyclic number.

It is not a de Polignac number, because 82566117525821 - 2⁶ = 82566117525757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82566117521821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41283058762910 + 41283058762911.

It is an arithmetic number, because the mean of its divisors is an integer number (41283058762911).

Almost surely, 2^{82566117525821} is an apocalyptic number.

It is an amenable number.

82566117525821 is a deficient number, since it is larger than the sum of its proper divisors (1).

82566117525821 is an equidigital number, since it uses as much as digits as its factorization.

82566117525821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128000, while the sum is 59.

The spelling of 82566117525821 in words is "eighty-two trillion, five hundred sixty-six billion, one hundred seventeen million, five hundred twenty-five thousand, eight hundred twenty-one".