66506556023 has 4 divisors (see below), whose sum is σ = 66534537600. Its totient is φ = 66478574448.

The previous prime is 66506556013. The next prime is 66506556037. The reversal of 66506556023 is 32065560566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66506556023 - 2¹⁰ = 66506554999 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 (66506556013) 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, 13987223 + ... + 13991976.

It is an arithmetic number, because the mean of its divisors is an integer number (16633634400).

Almost surely, 2^66506556023 is an apocalyptic number.

66506556023 is a deficient number, since it is larger than the sum of its proper divisors (27981577).

66506556023 is a wasteful number, since it uses less digits than its factorization.

66506556023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27981576.

The product of its (nonzero) digits is 972000, while the sum is 44.

The spelling of 66506556023 in words is "sixty-six billion, five hundred six million, five hundred fifty-six thousand, twenty-three".