66646294643 has 4 divisors (see below), whose sum is σ = 68064300960. Its totient is φ = 65228288328.

The previous prime is 66646294633. The next prime is 66646294717. The reversal of 66646294643 is 34649264666.

66646294643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34649264666 = 2 ⋅17324632333.

It is a cyclic number.

It is not a de Polignac number, because 66646294643 - 2¹² = 66646290547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66646294613) 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, 709003088 + ... + 709003181.

It is an arithmetic number, because the mean of its divisors is an integer number (17016075240).

Almost surely, 2^66646294643 is an apocalyptic number.

66646294643 is a deficient number, since it is larger than the sum of its proper divisors (1418006317).

66646294643 is a wasteful number, since it uses less digits than its factorization.

66646294643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1418006316.

The product of its digits is 26873856, while the sum is 56.

The spelling of 66646294643 in words is "sixty-six billion, six hundred forty-six million, two hundred ninety-four thousand, six hundred forty-three".