28400825 has 12 divisors (see below), whose sum is σ = 35317308. Its totient is φ = 22656000.

The previous prime is 28400819. The next prime is 28400843. The reversal of 28400825 is 52800482.

It can be written as a sum of positive squares in 6 ways, for example, as 606841 + 27793984 = 779^2 + 5272^2 .

It is not a de Polignac number, because 28400825 - 2⁸ = 28400569 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8609 + ... + 11441.

It is an arithmetic number, because the mean of its divisors is an integer number (2943109).

Almost surely, 2^28400825 is an apocalyptic number.

28400825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28400825 is a deficient number, since it is larger than the sum of its proper divisors (6916483).

28400825 is a wasteful number, since it uses less digits than its factorization.

28400825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3244 (or 3239 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 29.

The square root of 28400825 is about 5329.2424414733. The cubic root of 28400825 is about 305.1010146461.

The spelling of 28400825 in words is "twenty-eight million, four hundred thousand, eight hundred twenty-five".