21525075 has 96 divisors (see below), whose sum is σ = 46663680. Its totient is φ = 9590400.

The previous prime is 21525071. The next prime is 21525089. The reversal of 21525075 is 57052512.

It is a happy number.

21525075 is a `hidden beast` number, since 2 + 152 + 507 + 5 = 666.

It is not a de Polignac number, because 21525075 - 2² = 21525071 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21525071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 96414 + ... + 96636.

It is an arithmetic number, because the mean of its divisors is an integer number (486080).

Almost surely, 2^21525075 is an apocalyptic number.

21525075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21525075 is an abundant number, since it is smaller than the sum of its proper divisors (25138605).

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

21525075 is a wasteful number, since it uses less digits than its factorization.

21525075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266 (or 255 counting only the distinct ones).

The product of its (nonzero) digits is 3500, while the sum is 27.

The square root of 21525075 is about 4639.5123666179. The cubic root of 21525075 is about 278.1729467479.

Adding to 21525075 its reverse (57052512), we get a palindrome (78577587).

It can be divided in two parts, 2152507 and 5, that added together give a palindrome (2152512).

The spelling of 21525075 in words is "twenty-one million, five hundred twenty-five thousand, seventy-five".