28109216922109 has 4 divisors (see below), whose sum is σ = 28121390686620. Its totient is φ = 28097043157600.

The previous prime is 28109216922067. The next prime is 28109216922139. The reversal of 28109216922109 is 90122961290182.

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 26142799678009 + 1966417244100 = 5113003^2 + 1402290^2 .

It is a cyclic number.

It is not a de Polignac number, because 28109216922109 - 2²⁵ = 28109183367677 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 (28109216922139) 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, 6086878792 + ... + 6086883409.

It is an arithmetic number, because the mean of its divisors is an integer number (7030347671655).

Almost surely, 2^{28109216922109} is an apocalyptic number.

It is an amenable number.

28109216922109 is a deficient number, since it is larger than the sum of its proper divisors (12173764511).

28109216922109 is a wasteful number, since it uses less digits than its factorization.

28109216922109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12173764510.

The product of its (nonzero) digits is 559872, while the sum is 52.

The spelling of 28109216922109 in words is "twenty-eight trillion, one hundred nine billion, two hundred sixteen million, nine hundred twenty-two thousand, one hundred nine".