16665188677 has 4 divisors (see below), whose sum is σ = 16669581516. Its totient is φ = 16660795840.

The previous prime is 16665188663. The next prime is 16665188699. The reversal of 16665188677 is 77688156661.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 9255594436 + 7409594241 = 96206^2 + 86079^2 .

It is a cyclic number.

It is not a de Polignac number, because 16665188677 - 2⁷ = 16665188549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16665188977) 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, 2190724 + ... + 2198317.

It is an arithmetic number, because the mean of its divisors is an integer number (4167395379).

Almost surely, 2^16665188677 is an apocalyptic number.

It is an amenable number.

16665188677 is a deficient number, since it is larger than the sum of its proper divisors (4392839).

16665188677 is an equidigital number, since it uses as much as digits as its factorization.

16665188677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4392838.

The product of its digits is 20321280, while the sum is 61.

The spelling of 16665188677 in words is "sixteen billion, six hundred sixty-five million, one hundred eighty-eight thousand, six hundred seventy-seven".