66134656634665 has 4 divisors (see below), whose sum is σ = 79361587961604. Its totient is φ = 52907725307728.

The previous prime is 66134656634659. The next prime is 66134656634687. The reversal of 66134656634665 is 56643665643166.

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 34564945606416 + 31569711028249 = 5879196^2 + 5618693^2 .

It is a cyclic number.

It is not a de Polignac number, because 66134656634665 - 2⁵ = 66134656634633 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66134656634665.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6613465663462 + ... + 6613465663471.

It is an arithmetic number, because the mean of its divisors is an integer number (19840396990401).

Almost surely, 2^{66134656634665} is an apocalyptic number.

It is an amenable number.

66134656634665 is a deficient number, since it is larger than the sum of its proper divisors (13226931326939).

66134656634665 is a wasteful number, since it uses less digits than its factorization.

66134656634665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13226931326938.

The product of its digits is 1007769600, while the sum is 67.

The spelling of 66134656634665 in words is "sixty-six trillion, one hundred thirty-four billion, six hundred fifty-six million, six hundred thirty-four thousand, six hundred sixty-five".