85578844443221 has 2 divisors, whose sum is σ = 85578844443222. Its totient is φ = 85578844443220.

The previous prime is 85578844443167. The next prime is 85578844443247. The reversal of 85578844443221 is 12234444887558.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75055989672196 + 10522854771025 = 8663486^2 + 3243895^2 .

It is a cyclic number.

It is not a de Polignac number, because 85578844443221 - 2²² = 85578840248917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85578844443721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42789422221610 + 42789422221611.

It is an arithmetic number, because the mean of its divisors is an integer number (42789422221611).

Almost surely, 2^{85578844443221} is an apocalyptic number.

It is an amenable number.

85578844443221 is a deficient number, since it is larger than the sum of its proper divisors (1).

85578844443221 is an equidigital number, since it uses as much as digits as its factorization.

85578844443221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 275251200, while the sum is 65.

The spelling of 85578844443221 in words is "eighty-five trillion, five hundred seventy-eight billion, eight hundred forty-four million, four hundred forty-three thousand, two hundred twenty-one".