28225540 has 24 divisors (see below), whose sum is σ = 67741632. Its totient is φ = 9677280.

The previous prime is 28225537. The next prime is 28225543. The reversal of 28225540 is 4552282.

It is an interprime number because it is at equal distance from previous prime (28225537) and next prime (28225543).

It is a super-2 number, since 2×28225540² = 1593362216583200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 28225499 and 28225508.

It is not an unprimeable number, because it can be changed into a prime (28225543) 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, 100666 + ... + 100945.

It is an arithmetic number, because the mean of its divisors is an integer number (2822568).

Almost surely, 2^28225540 is an apocalyptic number.

28225540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28225540 is an abundant number, since it is smaller than the sum of its proper divisors (39516092).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28225540 is a wasteful number, since it uses less digits than its factorization.

28225540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201627 (or 201625 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 28.

The square root of 28225540 is about 5312.7714048319. The cubic root of 28225540 is about 304.4720419253.

The spelling of 28225540 in words is "twenty-eight million, two hundred twenty-five thousand, five hundred forty".