66635256654145 has 4 divisors (see below), whose sum is σ = 79962307984980. Its totient is φ = 53308205323312.

The previous prime is 66635256654143. The next prime is 66635256654167. The reversal of 66635256654145 is 54145665253666.

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 29296325361664 + 37338931292481 = 5412608^2 + 6110559^2 .

It is a cyclic number.

It is not a de Polignac number, because 66635256654145 - 2¹ = 66635256654143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66635256654143) 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, 6663525665410 + ... + 6663525665419.

It is an arithmetic number, because the mean of its divisors is an integer number (19990576996245).

Almost surely, 2^{66635256654145} is an apocalyptic number.

It is an amenable number.

66635256654145 is a deficient number, since it is larger than the sum of its proper divisors (13327051330835).

66635256654145 is a wasteful number, since it uses less digits than its factorization.

66635256654145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13327051330834.

The product of its digits is 466560000, while the sum is 64.

The spelling of 66635256654145 in words is "sixty-six trillion, six hundred thirty-five billion, two hundred fifty-six million, six hundred fifty-four thousand, one hundred forty-five".