28420925 has 24 divisors (see below), whose sum is σ = 38263176. Its totient is φ = 20816640.

The previous prime is 28420919. The next prime is 28420927. The reversal of 28420925 is 52902482.

It can be written as a sum of positive squares in 12 ways, for example, as 22080601 + 6340324 = 4699^2 + 2518^2 .

It is not a de Polignac number, because 28420925 - 2⁸ = 28420669 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28420891 and 28420900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28420927) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50747 + ... + 51303.

It is an arithmetic number, because the mean of its divisors is an integer number (1594299).

Almost surely, 2^28420925 is an apocalyptic number.

28420925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28420925 is a deficient number, since it is larger than the sum of its proper divisors (9842251).

28420925 is a wasteful number, since it uses less digits than its factorization.

28420925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 737 (or 732 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 28420925 is about 5331.1279294348. The cubic root of 28420925 is about 305.1729736384.

The spelling of 28420925 in words is "twenty-eight million, four hundred twenty thousand, nine hundred twenty-five".