28440404 has 6 divisors (see below), whose sum is σ = 49770714. Its totient is φ = 14220200.

The previous prime is 28440367. The next prime is 28440407. The reversal of 28440404 is 40404482.

It can be written as a sum of positive squares in only one way, i.e., 20611600 + 7828804 = 4540^2 + 2798^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28440407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3555047 + ... + 3555054.

It is an arithmetic number, because the mean of its divisors is an integer number (8295119).

Almost surely, 2^28440404 is an apocalyptic number.

It is an amenable number.

28440404 is a deficient number, since it is larger than the sum of its proper divisors (21330310).

28440404 is a wasteful number, since it uses less digits than its factorization.

28440404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7110105 (or 7110103 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 26.

The square root of 28440404 is about 5332.9545282142. The cubic root of 28440404 is about 305.2426770559.

Adding to 28440404 its reverse (40404482), we get a palindrome (68844886).

The spelling of 28440404 in words is "twenty-eight million, four hundred forty thousand, four hundred four".