66542366489 has 4 divisors (see below), whose sum is σ = 66665365860. Its totient is φ = 66419367120.

The previous prime is 66542366477. The next prime is 66542366503. The reversal of 66542366489 is 98466324566.

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

It can be written as a sum of positive squares in 2 ways, for example, as 45938634889 + 20603731600 = 214333^2 + 143540^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66542366489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66542366389) 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, 61498874 + ... + 61499955.

It is an arithmetic number, because the mean of its divisors is an integer number (16666341465).

Almost surely, 2^66542366489 is an apocalyptic number.

It is an amenable number.

66542366489 is a deficient number, since it is larger than the sum of its proper divisors (122999371).

66542366489 is a wasteful number, since it uses less digits than its factorization.

66542366489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122999370.

The product of its digits is 44789760, while the sum is 59.

The spelling of 66542366489 in words is "sixty-six billion, five hundred forty-two million, three hundred sixty-six thousand, four hundred eighty-nine".