66044360691 has 16 divisors (see below), whose sum is σ = 97850340000. Its totient is φ = 44026494624.

The previous prime is 66044360671. The next prime is 66044360699. The reversal of 66044360691 is 19606344066.

66044360691 is a `hidden beast` number, since 6 + 60 + 443 + 60 + 6 + 91 = 666.

It is not a de Polignac number, because 66044360691 - 2¹¹ = 66044358643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66044360699) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 347565 + ... + 502881.

It is an arithmetic number, because the mean of its divisors is an integer number (6115646250).

Almost surely, 2^66044360691 is an apocalyptic number.

66044360691 is a deficient number, since it is larger than the sum of its proper divisors (31805979309).

66044360691 is a wasteful number, since it uses less digits than its factorization.

66044360691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171075 (or 171069 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 45.

The spelling of 66044360691 in words is "sixty-six billion, forty-four million, three hundred sixty thousand, six hundred ninety-one".