28140923 has 4 divisors (see below), whose sum is σ = 28419648. Its totient is φ = 27862200.

The previous prime is 28140913. The next prime is 28140929. The reversal of 28140923 is 32904182.

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 28140923 - 2⁴ = 28140907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28140929) 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, 139211 + ... + 139412.

It is an arithmetic number, because the mean of its divisors is an integer number (7104912).

Almost surely, 2^28140923 is an apocalyptic number.

28140923 is a deficient number, since it is larger than the sum of its proper divisors (278725).

28140923 is a wasteful number, since it uses less digits than its factorization.

28140923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278724.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 28140923 is about 5304.8018813147. The cubic root of 28140923 is about 304.1674797084.

The spelling of 28140923 in words is "twenty-eight million, one hundred forty thousand, nine hundred twenty-three".