66216697 has 2 divisors, whose sum is σ = 66216698. Its totient is φ = 66216696.

The previous prime is 66216679. The next prime is 66216727. The reversal of 66216697 is 79661266.

Together with previous prime (66216679) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66194496 + 22201 = 8136^2 + 149^2 .

It is a cyclic number.

It is not a de Polignac number, because 66216697 - 2¹⁹ = 65692409 is a prime.

It is not a weakly prime, because it can be changed into another prime (66216607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33108348 + 33108349.

It is an arithmetic number, because the mean of its divisors is an integer number (33108349).

Almost surely, 2^66216697 is an apocalyptic number.

It is an amenable number.

66216697 is a deficient number, since it is larger than the sum of its proper divisors (1).

66216697 is an equidigital number, since it uses as much as digits as its factorization.

66216697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 163296, while the sum is 43.

The square root of 66216697 is about 8137.3642538601. The cubic root of 66216697 is about 404.5658040392.

The spelling of 66216697 in words is "sixty-six million, two hundred sixteen thousand, six hundred ninety-seven".