66136064657 has 4 divisors (see below), whose sum is σ = 71223454260. Its totient is φ = 61048675056.

The previous prime is 66136064651. The next prime is 66136064677. The reversal of 66136064657 is 75646063166.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13932497296 + 52203567361 = 118036^2 + 228481^2 .

It is a cyclic number.

It is not a de Polignac number, because 66136064657 - 2⁶ = 66136064593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66136064651) 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, 2543694782 + ... + 2543694807.

It is an arithmetic number, because the mean of its divisors is an integer number (17805863565).

Almost surely, 2^66136064657 is an apocalyptic number.

It is an amenable number.

66136064657 is a deficient number, since it is larger than the sum of its proper divisors (5087389603).

66136064657 is a wasteful number, since it uses less digits than its factorization.

66136064657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5087389602.

The product of its (nonzero) digits is 3265920, while the sum is 50.

The spelling of 66136064657 in words is "sixty-six billion, one hundred thirty-six million, sixty-four thousand, six hundred fifty-seven".