66450745693 has 2 divisors, whose sum is σ = 66450745694. Its totient is φ = 66450745692.

The previous prime is 66450745607. The next prime is 66450745703. The reversal of 66450745693 is 39654705466.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55723379364 + 10727366329 = 236058^2 + 103573^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66450745693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66450745093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33225372846 + 33225372847.

It is an arithmetic number, because the mean of its divisors is an integer number (33225372847).

Almost surely, 2^66450745693 is an apocalyptic number.

It is an amenable number.

66450745693 is a deficient number, since it is larger than the sum of its proper divisors (1).

66450745693 is an equidigital number, since it uses as much as digits as its factorization.

66450745693 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16329600, while the sum is 55.

The spelling of 66450745693 in words is "sixty-six billion, four hundred fifty million, seven hundred forty-five thousand, six hundred ninety-three".