66138263 has 2 divisors, whose sum is σ = 66138264. Its totient is φ = 66138262.

The previous prime is 66138251. The next prime is 66138307. The reversal of 66138263 is 36283166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66138263 - 2¹⁸ = 65876119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66132263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33069131 + 33069132.

It is an arithmetic number, because the mean of its divisors is an integer number (33069132).

Almost surely, 2^66138263 is an apocalyptic number.

66138263 is a deficient number, since it is larger than the sum of its proper divisors (1).

66138263 is an equidigital number, since it uses as much as digits as its factorization.

66138263 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 35.

The square root of 66138263 is about 8132.5434520819. The cubic root of 66138263 is about 404.4060042065.

The spelling of 66138263 in words is "sixty-six million, one hundred thirty-eight thousand, two hundred sixty-three".