28091929 has 4 divisors (see below), whose sum is σ = 28777140. Its totient is φ = 27406720.

The previous prime is 28091927. The next prime is 28091941. The reversal of 28091929 is 92919082.

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 13307904 + 14784025 = 3648^2 + 3845^2 .

It is a cyclic number.

It is not a de Polignac number, because 28091929 - 2¹ = 28091927 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28091891 and 28091900.

It is not an unprimeable number, because it can be changed into a prime (28091927) 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, 342544 + ... + 342625.

It is an arithmetic number, because the mean of its divisors is an integer number (7194285).

Almost surely, 2^28091929 is an apocalyptic number.

It is an amenable number.

28091929 is a deficient number, since it is larger than the sum of its proper divisors (685211).

28091929 is an equidigital number, since it uses as much as digits as its factorization.

28091929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685210.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 28091929 is about 5300.1819780079. The cubic root of 28091929 is about 303.9908562866.

The spelling of 28091929 in words is "twenty-eight million, ninety-one thousand, nine hundred twenty-nine".