28138025 has 12 divisors (see below), whose sum is σ = 34968000. Its totient is φ = 22460880.

The previous prime is 28138021. The next prime is 28138027. The reversal of 28138025 is 52083182.

It is not a de Polignac number, because 28138025 - 2² = 28138021 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28138021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14036 + ... + 15914.

It is an arithmetic number, because the mean of its divisors is an integer number (2914000).

Almost surely, 2^28138025 is an apocalyptic number.

28138025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28138025 is a deficient number, since it is larger than the sum of its proper divisors (6829975).

28138025 is a wasteful number, since it uses less digits than its factorization.

28138025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2488 (or 2483 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 28138025 is about 5304.5287255326. The cubic root of 28138025 is about 304.1570381223.

The spelling of 28138025 in words is "twenty-eight million, one hundred thirty-eight thousand, twenty-five".