66506505656494 has 8 divisors (see below), whose sum is σ = 100157207722488. Its totient is φ = 33120769749000.

The previous prime is 66506505656491. The next prime is 66506505656509. The reversal of 66506505656494 is 49465650560566.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66506505656491) 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, 66241538997 + ... + 66241540000.

It is an arithmetic number, because the mean of its divisors is an integer number (12519650965311).

Almost surely, 2^{66506505656494} is an apocalyptic number.

66506505656494 is a deficient number, since it is larger than the sum of its proper divisors (33650702065994).

66506505656494 is a wasteful number, since it uses less digits than its factorization.

66506505656494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132483079250.

The product of its (nonzero) digits is 699840000, while the sum is 67.

The spelling of 66506505656494 in words is "sixty-six trillion, five hundred six billion, five hundred five million, six hundred fifty-six thousand, four hundred ninety-four".