28021125 has 32 divisors (see below), whose sum is σ = 50873472. Its totient is φ = 13584000.

The previous prime is 28021121. The next prime is 28021139. The reversal of 28021125 is 52112082.

It is a happy number.

It is not a de Polignac number, because 28021125 - 2² = 28021121 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28021121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 729 + ... + 7521.

It is an arithmetic number, because the mean of its divisors is an integer number (1589796).

Almost surely, 2^28021125 is an apocalyptic number.

28021125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28021125 is a deficient number, since it is larger than the sum of its proper divisors (22852347).

28021125 is a wasteful number, since it uses less digits than its factorization.

28021125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6822 (or 6812 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 28021125 is about 5293.4983706430. The cubic root of 28021125 is about 303.7352445880.

The spelling of 28021125 in words is "twenty-eight million, twenty-one thousand, one hundred twenty-five".