28236505 has 16 divisors (see below), whose sum is σ = 38158848. Its totient is φ = 19872000.

The previous prime is 28236493. The next prime is 28236539. The reversal of 28236505 is 50563282.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-28236505 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6576 + ... + 9985.

It is an arithmetic number, because the mean of its divisors is an integer number (2384928).

Almost surely, 2^28236505 is an apocalyptic number.

It is an amenable number.

28236505 is a deficient number, since it is larger than the sum of its proper divisors (9922343).

28236505 is a wasteful number, since it uses less digits than its factorization.

28236505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16608.

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 28236505 is about 5313.8032519091. The cubic root of 28236505 is about 304.5114637128.

Adding to 28236505 its reverse (50563282), we get a palindrome (78799787).

The spelling of 28236505 in words is "twenty-eight million, two hundred thirty-six thousand, five hundred five".