66138923527 has 4 divisors (see below), whose sum is σ = 66793764456. Its totient is φ = 65484082600.

The previous prime is 66138923509. The next prime is 66138923659. The reversal of 66138923527 is 72532983166.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66138923527 - 2²³ = 66130534919 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66138923927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 327420313 + ... + 327420514.

It is an arithmetic number, because the mean of its divisors is an integer number (16698441114).

Almost surely, 2^66138923527 is an apocalyptic number.

66138923527 is a deficient number, since it is larger than the sum of its proper divisors (654840929).

66138923527 is a wasteful number, since it uses less digits than its factorization.

66138923527 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 654840928.

The product of its digits is 3265920, while the sum is 52.

The spelling of 66138923527 in words is "sixty-six billion, one hundred thirty-eight million, nine hundred twenty-three thousand, five hundred twenty-seven".