21152535 has 8 divisors (see below), whose sum is σ = 33844080. Its totient is φ = 11281344.

The previous prime is 21152519. The next prime is 21152561. The reversal of 21152535 is 53525112.

It is a happy number.

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

It is not a de Polignac number, because 21152535 - 2⁴ = 21152519 is a prime.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 705070 + ... + 705099.

It is an arithmetic number, because the mean of its divisors is an integer number (4230510).

Almost surely, 2^21152535 is an apocalyptic number.

21152535 is a deficient number, since it is larger than the sum of its proper divisors (12691545).

21152535 is a wasteful number, since it uses less digits than its factorization.

21152535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1410177.

The product of its digits is 1500, while the sum is 24.

The square root of 21152535 is about 4599.1885153796. The cubic root of 21152535 is about 276.5587949007.

Adding to 21152535 its reverse (53525112), we get a palindrome (74677647).

The spelling of 21152535 in words is "twenty-one million, one hundred fifty-two thousand, five hundred thirty-five".