28909405 has 8 divisors (see below), whose sum is σ = 39647232. Its totient is φ = 19823568.

The previous prime is 28909399. The next prime is 28909409. The reversal of 28909405 is 50490982.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28909405 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28909409) 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, 412957 + ... + 413026.

It is an arithmetic number, because the mean of its divisors is an integer number (4955904).

Almost surely, 2^28909405 is an apocalyptic number.

It is an amenable number.

28909405 is a deficient number, since it is larger than the sum of its proper divisors (10737827).

28909405 is an equidigital number, since it uses as much as digits as its factorization.

28909405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825995.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 28909405 is about 5376.7466929362. The cubic root of 28909405 is about 306.9114217814.

The spelling of 28909405 in words is "twenty-eight million, nine hundred nine thousand, four hundred five".