28249645 has 8 divisors (see below), whose sum is σ = 33930360. Its totient is φ = 22579200.

The previous prime is 28249643. The next prime is 28249657. The reversal of 28249645 is 54694282.

It can be written as a sum of positive squares in 4 ways, for example, as 5391684 + 22857961 = 2322^2 + 4781^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28249645 - 2¹ = 28249643 is a prime.

It is a super-3 number, since 3×28249645³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28249598 and 28249607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28249643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6241 + ... + 9769.

It is an arithmetic number, because the mean of its divisors is an integer number (4241295).

Almost surely, 2^28249645 is an apocalyptic number.

It is an amenable number.

28249645 is a deficient number, since it is larger than the sum of its proper divisors (5680715).

28249645 is a wasteful number, since it uses less digits than its factorization.

28249645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5135.

The product of its digits is 138240, while the sum is 40.

The square root of 28249645 is about 5315.0395106716. The cubic root of 28249645 is about 304.5586917027.

The spelling of 28249645 in words is "twenty-eight million, two hundred forty-nine thousand, six hundred forty-five".