28192730091 has 4 divisors (see below), whose sum is σ = 37590306792. Its totient is φ = 18795153392.

The previous prime is 28192730051. The next prime is 28192730099. The reversal of 28192730091 is 19003729182.

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

It is a cyclic number.

It is not a de Polignac number, because 28192730091 - 2¹¹ = 28192728043 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28192730099) 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, 4698788346 + ... + 4698788351.

It is an arithmetic number, because the mean of its divisors is an integer number (9397576698).

Almost surely, 2^28192730091 is an apocalyptic number.

28192730091 is a deficient number, since it is larger than the sum of its proper divisors (9397576701).

28192730091 is an equidigital number, since it uses as much as digits as its factorization.

28192730091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9397576700.

The product of its (nonzero) digits is 54432, while the sum is 42.

The spelling of 28192730091 in words is "twenty-eight billion, one hundred ninety-two million, seven hundred thirty thousand, ninety-one".