28445405 has 8 divisors (see below), whose sum is σ = 34263000. Its totient is φ = 22670656.

The previous prime is 28445401. The next prime is 28445429. The reversal of 28445405 is 50454482.

It can be written as a sum of positive squares in 4 ways, for example, as 840889 + 27604516 = 917^2 + 5254^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 28445405 - 2² = 28445401 is a prime.

It is a super-2 number, since 2×28445405² = 1618282131228050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28445401) 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 7 ways as a sum of consecutive naturals, for example, 9230 + ... + 11919.

It is an arithmetic number, because the mean of its divisors is an integer number (4282875).

Almost surely, 2^28445405 is an apocalyptic number.

It is an amenable number.

28445405 is a deficient number, since it is larger than the sum of its proper divisors (5817595).

28445405 is a wasteful number, since it uses less digits than its factorization.

28445405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21423.

The product of its (nonzero) digits is 25600, while the sum is 32.

The square root of 28445405 is about 5333.4233846564. The cubic root of 28445405 is about 305.2605674390.

Adding to 28445405 its reverse (50454482), we get a palindrome (78899887).

The spelling of 28445405 in words is "twenty-eight million, four hundred forty-five thousand, four hundred five".