66666604423 has 2 divisors, whose sum is σ = 66666604424. Its totient is φ = 66666604422.

The previous prime is 66666604397. The next prime is 66666604513. The reversal of 66666604423 is 32440666666.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66666604423 is a prime.

It is a super-2 number, since 2×66666604423² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66666604223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33333302211 + 33333302212.

It is an arithmetic number, because the mean of its divisors is an integer number (33333302212).

Almost surely, 2^66666604423 is an apocalyptic number.

66666604423 is a deficient number, since it is larger than the sum of its proper divisors (1).

66666604423 is an equidigital number, since it uses as much as digits as its factorization.

66666604423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4478976, while the sum is 49.

The spelling of 66666604423 in words is "sixty-six billion, six hundred sixty-six million, six hundred four thousand, four hundred twenty-three".