66218701 has 2 divisors, whose sum is σ = 66218702. Its totient is φ = 66218700.

The previous prime is 66218693. The next prime is 66218741. The reversal of 66218701 is 10781266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66096900 + 121801 = 8130^2 + 349^2 .

It is a cyclic number.

It is not a de Polignac number, because 66218701 - 2³ = 66218693 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66218741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33109350 + 33109351.

It is an arithmetic number, because the mean of its divisors is an integer number (33109351).

Almost surely, 2^66218701 is an apocalyptic number.

It is an amenable number.

66218701 is a deficient number, since it is larger than the sum of its proper divisors (1).

66218701 is an equidigital number, since it uses as much as digits as its factorization.

66218701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 66218701 is about 8137.4873886231. The cubic root of 66218701 is about 404.5698852943.

Adding to 66218701 its reverse (10781266), we get a palindrome (76999967).

The spelling of 66218701 in words is "sixty-six million, two hundred eighteen thousand, seven hundred one".