28404445 has 8 divisors (see below), whose sum is σ = 34259544. Its totient is φ = 22607424.

The previous prime is 28404407. The next prime is 28404451. The reversal of 28404445 is 54440482.

It can be written as a sum of positive squares in 4 ways, for example, as 12131289 + 16273156 = 3483^2 + 4034^2 .

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 28404445 - 2¹⁵ = 28371677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13434 + ... + 15403.

It is an arithmetic number, because the mean of its divisors is an integer number (4282443).

Almost surely, 2^28404445 is an apocalyptic number.

It is an amenable number.

28404445 is a deficient number, since it is larger than the sum of its proper divisors (5855099).

28404445 is a wasteful number, since it uses less digits than its factorization.

28404445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29039.

The product of its (nonzero) digits is 20480, while the sum is 31.

The square root of 28404445 is about 5329.5820661662. The cubic root of 28404445 is about 305.1139769309.

It can be divided in two parts, 284044 and 45, that added together give a square (284089 = 533²).

The spelling of 28404445 in words is "twenty-eight million, four hundred four thousand, four hundred forty-five".