66708569 has 2 divisors, whose sum is σ = 66708570. Its totient is φ = 66708568.

The previous prime is 66708553. The next prime is 66708589. The reversal of 66708569 is 96580766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61418569 + 5290000 = 7837^2 + 2300^2 .

It is a cyclic number.

It is not a de Polignac number, because 66708569 - 2⁴ = 66708553 is a prime.

It is a super-2 number, since 2×66708569² = 8900066356055522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66708539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33354284 + 33354285.

It is an arithmetic number, because the mean of its divisors is an integer number (33354285).

Almost surely, 2^66708569 is an apocalyptic number.

It is an amenable number.

66708569 is a deficient number, since it is larger than the sum of its proper divisors (1).

66708569 is an equidigital number, since it uses as much as digits as its factorization.

66708569 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 544320, while the sum is 47.

The square root of 66708569 is about 8167.5313895938. The cubic root of 66708569 is about 405.5650680643.

The spelling of 66708569 in words is "sixty-six million, seven hundred eight thousand, five hundred sixty-nine".