66791888040668 has 72 divisors (see below), whose sum is σ = 140407710735600. Its totient is φ = 27702886401792.

The previous prime is 66791888040643. The next prime is 66791888040673. The reversal of 66791888040668 is 86604088819766.

It is a super-2 number, since 2×66791888040668² (a number of 28 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 23 ways as a sum of consecutive naturals, for example, 35434553 + ... + 37271856.

It is an arithmetic number, because the mean of its divisors is an integer number (1950107093550).

Almost surely, 2^{66791888040668} is an apocalyptic number.

It is an amenable number.

66791888040668 is an abundant number, since it is smaller than the sum of its proper divisors (73615822694932).

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

66791888040668 is a wasteful number, since it uses less digits than its factorization.

66791888040668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72706579 (or 72706570 counting only the distinct ones).

The product of its (nonzero) digits is 1337720832, while the sum is 77.

The spelling of 66791888040668 in words is "sixty-six trillion, seven hundred ninety-one billion, eight hundred eighty-eight million, forty thousand, six hundred sixty-eight".