66217761733 has 2 divisors, whose sum is σ = 66217761734. Its totient is φ = 66217761732.

The previous prime is 66217761713. The next prime is 66217761749. The reversal of 66217761733 is 33716771266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66089098084 + 128663649 = 257078^2 + 11343^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66217761733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66217761713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33108880866 + 33108880867.

It is an arithmetic number, because the mean of its divisors is an integer number (33108880867).

Almost surely, 2^66217761733 is an apocalyptic number.

It is an amenable number.

66217761733 is a deficient number, since it is larger than the sum of its proper divisors (1).

66217761733 is an equidigital number, since it uses as much as digits as its factorization.

66217761733 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1333584, while the sum is 49.

The spelling of 66217761733 in words is "sixty-six billion, two hundred seventeen million, seven hundred sixty-one thousand, seven hundred thirty-three".