66040007644 has 144 divisors (see below), whose sum is σ = 140473025280. Its totient is φ = 26983756800.

The previous prime is 66040007611. The next prime is 66040007651. The reversal of 66040007644 is 44670004066.

66040007644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66040007644² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 32969547 + ... + 32971549.

It is an arithmetic number, because the mean of its divisors is an integer number (975507120).

Almost surely, 2^66040007644 is an apocalyptic number.

It is an amenable number.

66040007644 is an abundant number, since it is smaller than the sum of its proper divisors (74433017636).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66040007644 is a wasteful number, since it uses less digits than its factorization.

66040007644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2220 (or 2205 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 37.

The spelling of 66040007644 in words is "sixty-six billion, forty million, seven thousand, six hundred forty-four".