16661172206439 has 12 divisors (see below), whose sum is σ = 24066173955096. Its totient is φ = 11107431372912.

The previous prime is 16661172206411. The next prime is 16661172206453. The reversal of 16661172206439 is 93460227116661.

It is a happy number.

It is not a de Polignac number, because 16661172206439 - 2⁵ = 16661172206407 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661172206489) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8862817 + ... + 10576949.

It is an arithmetic number, because the mean of its divisors is an integer number (2005514496258).

Almost surely, 2^{16661172206439} is an apocalyptic number.

16661172206439 is a deficient number, since it is larger than the sum of its proper divisors (7405001748657).

16661172206439 is a wasteful number, since it uses less digits than its factorization.

16661172206439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2794126 (or 2794123 counting only the distinct ones).

The product of its (nonzero) digits is 3919104, while the sum is 54.

The spelling of 16661172206439 in words is "sixteen trillion, six hundred sixty-one billion, one hundred seventy-two million, two hundred six thousand, four hundred thirty-nine".