66534305623 has 4 divisors (see below), whose sum is σ = 66534866640. Its totient is φ = 66533744608.

The previous prime is 66534305599. The next prime is 66534305639. The reversal of 66534305623 is 32650343566.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 66534305623 - 2²¹ = 66532208471 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66534305623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66534305683) 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, 25090 + ... + 365647.

It is an arithmetic number, because the mean of its divisors is an integer number (16633716660).

Almost surely, 2^66534305623 is an apocalyptic number.

66534305623 is a deficient number, since it is larger than the sum of its proper divisors (561017).

66534305623 is a wasteful number, since it uses less digits than its factorization.

66534305623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 561016.

The product of its (nonzero) digits is 1166400, while the sum is 43.

The spelling of 66534305623 in words is "sixty-six billion, five hundred thirty-four million, three hundred five thousand, six hundred twenty-three".