66823393631 has 2 divisors, whose sum is σ = 66823393632. Its totient is φ = 66823393630.

The previous prime is 66823393619. The next prime is 66823393691. The reversal of 66823393631 is 13639332866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66823393631 - 2¹⁰ = 66823392607 is a prime.

It is a super-2 number, since 2×66823393631² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66823393631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66823393691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33411696815 + 33411696816.

It is an arithmetic number, because the mean of its divisors is an integer number (33411696816).

Almost surely, 2^66823393631 is an apocalyptic number.

66823393631 is a deficient number, since it is larger than the sum of its proper divisors (1).

66823393631 is an equidigital number, since it uses as much as digits as its factorization.

66823393631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2519424, while the sum is 50.

The spelling of 66823393631 in words is "sixty-six billion, eight hundred twenty-three million, three hundred ninety-three thousand, six hundred thirty-one".