85565573281 has 2 divisors, whose sum is σ = 85565573282. Its totient is φ = 85565573280.

The previous prime is 85565573251. The next prime is 85565573309. The reversal of 85565573281 is 18237556558.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80826490000 + 4739083281 = 284300^2 + 68841^2 .

It is a cyclic number.

It is not a de Polignac number, because 85565573281 - 2⁹ = 85565572769 is a prime.

It is a super-2 number, since 2×85565573281² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (85565573201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42782786640 + 42782786641.

It is an arithmetic number, because the mean of its divisors is an integer number (42782786641).

Almost surely, 2^85565573281 is an apocalyptic number.

It is an amenable number.

85565573281 is a deficient number, since it is larger than the sum of its proper divisors (1).

85565573281 is an equidigital number, since it uses as much as digits as its factorization.

85565573281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080000, while the sum is 55.

The spelling of 85565573281 in words is "eighty-five billion, five hundred sixty-five million, five hundred seventy-three thousand, two hundred eighty-one".