28055497 has 4 divisors (see below), whose sum is σ = 28584900. Its totient is φ = 27526096.

The previous prime is 28055483. The next prime is 28055539. The reversal of 28055497 is 79455082.

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 8128201 + 19927296 = 2851^2 + 4464^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28055497 is a prime.

It is a super-2 number, since 2×28055497² = 1574221823834018, which contains 22 as substring.

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 not an unprimeable number, because it can be changed into a prime (28055897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264622 + ... + 264727.

It is an arithmetic number, because the mean of its divisors is an integer number (7146225).

Almost surely, 2^28055497 is an apocalyptic number.

It is an amenable number.

28055497 is a deficient number, since it is larger than the sum of its proper divisors (529403).

28055497 is an equidigital number, since it uses as much as digits as its factorization.

28055497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 529402.

The product of its (nonzero) digits is 100800, while the sum is 40.

The square root of 28055497 is about 5296.7439998550. The cubic root of 28055497 is about 303.8593857138.

The spelling of 28055497 in words is "twenty-eight million, fifty-five thousand, four hundred ninety-seven".