28172164691 has 8 divisors (see below), whose sum is σ = 30735289344. Its totient is φ = 25609376520.

The previous prime is 28172164679. The next prime is 28172164723. The reversal of 28172164691 is 19646127182.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28172164691 - 2⁶ = 28172164627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28172164591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110546 + ... + 261848.

It is an arithmetic number, because the mean of its divisors is an integer number (3841911168).

Almost surely, 2^28172164691 is an apocalyptic number.

28172164691 is a deficient number, since it is larger than the sum of its proper divisors (2563124653).

28172164691 is a wasteful number, since it uses less digits than its factorization.

28172164691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168241.

The product of its digits is 290304, while the sum is 47.

The spelling of 28172164691 in words is "twenty-eight billion, one hundred seventy-two million, one hundred sixty-four thousand, six hundred ninety-one".