66040306645 has 4 divisors (see below), whose sum is σ = 79248367980. Its totient is φ = 52832245312.

The previous prime is 66040306639. The next prime is 66040306669. The reversal of 66040306645 is 54660304066.

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 18637437361 + 47402869284 = 136519^2 + 217722^2 .

It is a cyclic number.

It is not a de Polignac number, because 66040306645 - 2⁹ = 66040306133 is a prime.

It is a super-2 number, since 2×66040306645² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 66040306598 and 66040306607.

It is a congruent number.

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, 6604030660 + ... + 6604030669.

It is an arithmetic number, because the mean of its divisors is an integer number (19812091995).

Almost surely, 2^66040306645 is an apocalyptic number.

It is an amenable number.

66040306645 is a deficient number, since it is larger than the sum of its proper divisors (13208061335).

66040306645 is a wasteful number, since it uses less digits than its factorization.

66040306645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13208061334.

The product of its (nonzero) digits is 311040, while the sum is 40.

The spelling of 66040306645 in words is "sixty-six billion, forty million, three hundred six thousand, six hundred forty-five".