66822599581 has 2 divisors, whose sum is σ = 66822599582. Its totient is φ = 66822599580.

The previous prime is 66822599531. The next prime is 66822599587. The reversal of 66822599581 is 18599522866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45226827556 + 21595772025 = 212666^2 + 146955^2 .

It is a cyclic number.

It is not a de Polignac number, because 66822599581 - 2¹⁷ = 66822468509 is a prime.

It is a super-2 number, since 2×66822599581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66822599587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33411299790 + 33411299791.

It is an arithmetic number, because the mean of its divisors is an integer number (33411299791).

Almost surely, 2^66822599581 is an apocalyptic number.

It is an amenable number.

66822599581 is a deficient number, since it is larger than the sum of its proper divisors (1).

66822599581 is an equidigital number, since it uses as much as digits as its factorization.

66822599581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18662400, while the sum is 61.

The spelling of 66822599581 in words is "sixty-six billion, eight hundred twenty-two million, five hundred ninety-nine thousand, five hundred eighty-one".