66640061653 has 4 divisors (see below), whose sum is σ = 72698249088. Its totient is φ = 60581874220.

The previous prime is 66640061629. The next prime is 66640061681. The reversal of 66640061653 is 35616004666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66640061653 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 (66640061753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3029093701 + ... + 3029093722.

It is an arithmetic number, because the mean of its divisors is an integer number (18174562272).

Almost surely, 2^66640061653 is an apocalyptic number.

It is an amenable number.

66640061653 is a deficient number, since it is larger than the sum of its proper divisors (6058187435).

66640061653 is a wasteful number, since it uses less digits than its factorization.

66640061653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6058187434.

The product of its (nonzero) digits is 466560, while the sum is 43.

The spelling of 66640061653 in words is "sixty-six billion, six hundred forty million, sixty-one thousand, six hundred fifty-three".