28055537 has 4 divisors (see below), whose sum is σ = 28073460. Its totient is φ = 28037616.

The previous prime is 28055483. The next prime is 28055539. The reversal of 28055537 is 73555082.

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 12931216 + 15124321 = 3596^2 + 3889^2 .

It is a cyclic number.

It is not a de Polignac number, because 28055537 - 2⁶ = 28055473 is a prime.

It is a super-2 number, since 2×28055537² = 1574226312716738, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28055497 and 28055506.

It is not an unprimeable number, because it can be changed into a prime (28055539) 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, 6362 + ... + 9827.

It is an arithmetic number, because the mean of its divisors is an integer number (7018365).

Almost surely, 2^28055537 is an apocalyptic number.

It is an amenable number.

28055537 is a deficient number, since it is larger than the sum of its proper divisors (17923).

28055537 is a wasteful number, since it uses less digits than its factorization.

28055537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17922.

The product of its (nonzero) digits is 42000, while the sum is 35.

The square root of 28055537 is about 5296.7477757583. The cubic root of 28055537 is about 303.8595301224.

The spelling of 28055537 in words is "twenty-eight million, fifty-five thousand, five hundred thirty-seven".