66881932787 has 4 divisors (see below), whose sum is σ = 66882807696. Its totient is φ = 66881057880.

The previous prime is 66881932781. The next prime is 66881932807. The reversal of 66881932787 is 78723918866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66881932787 - 2⁴ = 66881932771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66881932781) 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, 310508 + ... + 479769.

It is an arithmetic number, because the mean of its divisors is an integer number (16720701924).

Almost surely, 2^66881932787 is an apocalyptic number.

66881932787 is a deficient number, since it is larger than the sum of its proper divisors (874909).

66881932787 is an equidigital number, since it uses as much as digits as its factorization.

66881932787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 874908.

The product of its digits is 48771072, while the sum is 65.

The spelling of 66881932787 in words is "sixty-six billion, eight hundred eighty-one million, nine hundred thirty-two thousand, seven hundred eighty-seven".