66498645793 has 4 divisors (see below), whose sum is σ = 66539976580. Its totient is φ = 66457315008.

The previous prime is 66498645739. The next prime is 66498645803. The reversal of 66498645793 is 39754689466.

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 42686452449 + 23812193344 = 206607^2 + 154312^2 .

It is a cyclic number.

It is not a de Polignac number, because 66498645793 - 2²¹ = 66496548641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66498646793) 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, 20662980 + ... + 20666197.

It is an arithmetic number, because the mean of its divisors is an integer number (16634994145).

Almost surely, 2^66498645793 is an apocalyptic number.

It is an amenable number.

66498645793 is a deficient number, since it is larger than the sum of its proper divisors (41330787).

66498645793 is a wasteful number, since it uses less digits than its factorization.

66498645793 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41330786.

The product of its digits is 235146240, while the sum is 67.

The spelling of 66498645793 in words is "sixty-six billion, four hundred ninety-eight million, six hundred forty-five thousand, seven hundred ninety-three".