21252135 has 8 divisors (see below), whose sum is σ = 34003440. Its totient is φ = 11334464.

The previous prime is 21252113. The next prime is 21252137. The reversal of 21252135 is 53125212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21252135 - 2¹⁷ = 21121063 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21252137) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 708390 + ... + 708419.

It is an arithmetic number, because the mean of its divisors is an integer number (4250430).

Almost surely, 2^21252135 is an apocalyptic number.

21252135 is a deficient number, since it is larger than the sum of its proper divisors (12751305).

21252135 is a wasteful number, since it uses less digits than its factorization.

21252135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1416817.

The product of its digits is 600, while the sum is 21.

The square root of 21252135 is about 4610.0037960939. The cubic root of 21252135 is about 276.9921887391.

Adding to 21252135 its reverse (53125212), we get a palindrome (74377347).

The spelling of 21252135 in words is "twenty-one million, two hundred fifty-two thousand, one hundred thirty-five".