66540669557 has 8 divisors (see below), whose sum is σ = 70055787360. Its totient is φ = 63026849520.

The previous prime is 66540669539. The next prime is 66540669583. The reversal of 66540669557 is 75596604566.

It is a happy number.

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 66540669557 - 2¹⁰ = 66540668533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66540669496 and 66540669505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66545669557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 218294 + ... + 425127.

It is an arithmetic number, because the mean of its divisors is an integer number (8756973420).

Almost surely, 2^66540669557 is an apocalyptic number.

It is an amenable number.

66540669557 is a deficient number, since it is larger than the sum of its proper divisors (3515117803).

66540669557 is a wasteful number, since it uses less digits than its factorization.

66540669557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 648883.

The product of its (nonzero) digits is 40824000, while the sum is 59.

The spelling of 66540669557 in words is "sixty-six billion, five hundred forty million, six hundred sixty-nine thousand, five hundred fifty-seven".