21252075 has 48 divisors (see below), whose sum is σ = 38497536. Its totient is φ = 10281600.

The previous prime is 21252059. The next prime is 21252079. The reversal of 21252075 is 57025212.

It is not a de Polignac number, because 21252075 - 2⁴ = 21252059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21252079) 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 47 ways as a sum of consecutive naturals, for example, 69072 + ... + 69378.

It is an arithmetic number, because the mean of its divisors is an integer number (802032).

Almost surely, 2^21252075 is an apocalyptic number.

21252075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21252075 is a deficient number, since it is larger than the sum of its proper divisors (17245461).

21252075 is a wasteful number, since it uses less digits than its factorization.

21252075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404 (or 399 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 21252075 is about 4609.9972885025. The cubic root of 21252075 is about 276.9919280666.

Adding to 21252075 its reverse (57025212), we get a palindrome (78277287).

It can be divided in two parts, 2125207 and 5, that added together give a palindrome (2125212).

The spelling of 21252075 in words is "twenty-one million, two hundred fifty-two thousand, seventy-five".