28921692121 has 8 divisors (see below), whose sum is σ = 33238019520. Its totient is φ = 24651529008.

The previous prime is 28921692109. The next prime is 28921692127. The reversal of 28921692121 is 12129612982.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28921692121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28921692127) 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, 11539726 + ... + 11542231.

It is an arithmetic number, because the mean of its divisors is an integer number (4154752440).

Almost surely, 2^28921692121 is an apocalyptic number.

It is an amenable number.

28921692121 is a deficient number, since it is larger than the sum of its proper divisors (4316327399).

28921692121 is a wasteful number, since it uses less digits than its factorization.

28921692121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23082143.

The product of its digits is 62208, while the sum is 43.

The spelling of 28921692121 in words is "twenty-eight billion, nine hundred twenty-one million, six hundred ninety-two thousand, one hundred twenty-one".