66518423 has 2 divisors, whose sum is σ = 66518424. Its totient is φ = 66518422.

The previous prime is 66518401. The next prime is 66518443. The reversal of 66518423 is 32481566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66518423 - 2¹⁶ = 66452887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66518443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33259211 + 33259212.

It is an arithmetic number, because the mean of its divisors is an integer number (33259212).

Almost surely, 2^66518423 is an apocalyptic number.

66518423 is a deficient number, since it is larger than the sum of its proper divisors (1).

66518423 is an equidigital number, since it uses as much as digits as its factorization.

66518423 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 35.

The square root of 66518423 is about 8155.8827235315. The cubic root of 66518423 is about 405.1793606815.

Adding to 66518423 its reverse (32481566), we get a palindrome (98999989).

The spelling of 66518423 in words is "sixty-six million, five hundred eighteen thousand, four hundred twenty-three".