66256660013 has 8 divisors (see below), whose sum is σ = 70180923960. Its totient is φ = 62335375360.

The previous prime is 66256659883. The next prime is 66256660039. The reversal of 66256660013 is 31006665266.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 25468010569 + 40788649444 = 159587^2 + 201962^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66256660013 - 2⁸ = 66256659757 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 (66256663013) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 698948 + ... + 788061.

It is an arithmetic number, because the mean of its divisors is an integer number (8772615495).

Almost surely, 2^66256660013 is an apocalyptic number.

It is an amenable number.

66256660013 is a deficient number, since it is larger than the sum of its proper divisors (3924263947).

66256660013 is a wasteful number, since it uses less digits than its factorization.

66256660013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1489647.

The product of its (nonzero) digits is 233280, while the sum is 41.

The spelling of 66256660013 in words is "sixty-six billion, two hundred fifty-six million, six hundred sixty thousand, thirteen".