82385805721 has 2 divisors, whose sum is σ = 82385805722. Its totient is φ = 82385805720.

The previous prime is 82385805683. The next prime is 82385805757. The reversal of 82385805721 is 12750858328.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80095226121 + 2290579600 = 283011^2 + 47860^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-82385805721 is a prime.

It is not a weakly prime, because it can be changed into another prime (82385805791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41192902860 + 41192902861.

It is an arithmetic number, because the mean of its divisors is an integer number (41192902861).

Almost surely, 2^82385805721 is an apocalyptic number.

It is an amenable number.

82385805721 is a deficient number, since it is larger than the sum of its proper divisors (1).

82385805721 is an equidigital number, since it uses as much as digits as its factorization.

82385805721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1075200, while the sum is 49.

The spelling of 82385805721 in words is "eighty-two billion, three hundred eighty-five million, eight hundred five thousand, seven hundred twenty-one".