28643225 has 24 divisors (see below), whose sum is σ = 39497472. Its totient is φ = 20462400.

The previous prime is 28643207. The next prime is 28643233. The reversal of 28643225 is 52234682.

It is not a de Polignac number, because 28643225 - 2¹⁸ = 28381081 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28643191 and 28643200.

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, 8654 + ... + 11496.

It is an arithmetic number, because the mean of its divisors is an integer number (1645728).

Almost surely, 2^28643225 is an apocalyptic number.

28643225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28643225 is a deficient number, since it is larger than the sum of its proper divisors (10854247).

28643225 is a wasteful number, since it uses less digits than its factorization.

28643225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2897 (or 2892 counting only the distinct ones).

The product of its digits is 23040, while the sum is 32.

The square root of 28643225 is about 5351.9365653939. The cubic root of 28643225 is about 305.9665654728.

The spelling of 28643225 in words is "twenty-eight million, six hundred forty-three thousand, two hundred twenty-five".