66069581 has 2 divisors, whose sum is σ = 66069582. Its totient is φ = 66069580.

The previous prime is 66069541. The next prime is 66069589. The reversal of 66069581 is 18596066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55636681 + 10432900 = 7459^2 + 3230^2 .

It is a cyclic number.

It is not a de Polignac number, because 66069581 - 2¹⁰ = 66068557 is a prime.

It is a super-2 number, since 2×66069581² = 8730379067031122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66069589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33034790 + 33034791.

It is an arithmetic number, because the mean of its divisors is an integer number (33034791).

Almost surely, 2^66069581 is an apocalyptic number.

It is an amenable number.

66069581 is a deficient number, since it is larger than the sum of its proper divisors (1).

66069581 is an equidigital number, since it uses as much as digits as its factorization.

66069581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 41.

The square root of 66069581 is about 8128.3196910555. The cubic root of 66069581 is about 404.2659691142.

The spelling of 66069581 in words is "sixty-six million, sixty-nine thousand, five hundred eighty-one".