28169405 has 24 divisors (see below), whose sum is σ = 37604952. Its totient is φ = 20240000.

The previous prime is 28169389. The next prime is 28169423. The reversal of 28169405 is 50496182.

It can be written as a sum of positive squares in 4 ways, for example, as 7027801 + 21141604 = 2651^2 + 4598^2 .

It is not a de Polignac number, because 28169405 - 2⁴ = 28169389 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60875 + ... + 61335.

It is an arithmetic number, because the mean of its divisors is an integer number (1566873).

Almost surely, 2^28169405 is an apocalyptic number.

It is an amenable number.

28169405 is a deficient number, since it is larger than the sum of its proper divisors (9435547).

28169405 is a wasteful number, since it uses less digits than its factorization.

28169405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589 (or 578 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 28169405 is about 5307.4857512762. The cubic root of 28169405 is about 304.2700631363.

It can be divided in two parts, 2816 and 9405, that added together give a palindrome (12221).

The spelling of 28169405 in words is "twenty-eight million, one hundred sixty-nine thousand, four hundred five".