28125405 has 48 divisors (see below), whose sum is σ = 60787584. Its totient is φ = 11687040.

The previous prime is 28125403. The next prime is 28125407. The reversal of 28125405 is 50452182.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28125403) and next prime (28125407).

It is not a de Polignac number, because 28125405 - 2¹ = 28125403 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28125403) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 594 + ... + 7523.

It is an arithmetic number, because the mean of its divisors is an integer number (1266408).

Almost surely, 2^28125405 is an apocalyptic number.

It is an amenable number.

28125405 is an abundant number, since it is smaller than the sum of its proper divisors (32662179).

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

28125405 is a wasteful number, since it uses less digits than its factorization.

28125405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8146 (or 8143 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 28125405 is about 5303.3390425278. The cubic root of 28125405 is about 304.1115595001. Note that the first 3 decimals are identical.

Adding to 28125405 its reverse (50452182), we get a palindrome (78577587).

It can be divided in two parts, 28125 and 405, that multiplied together give a 6-th power (11390625 = 15⁶).

The spelling of 28125405 in words is "twenty-eight million, one hundred twenty-five thousand, four hundred five".