21080535 has 96 divisors (see below), whose sum is σ = 43338240. Its totient is φ = 8692992.

The previous prime is 21080533. The next prime is 21080537. The reversal of 21080535 is 53508012.

It is an interprime number because it is at equal distance from previous prime (21080533) and next prime (21080537).

It is not a de Polignac number, because 21080535 - 2¹ = 21080533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21080533) 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 95 ways as a sum of consecutive naturals, for example, 490224 + ... + 490266.

It is an arithmetic number, because the mean of its divisors is an integer number (451440).

Almost surely, 2^21080535 is an apocalyptic number.

21080535 is an abundant number, since it is smaller than the sum of its proper divisors (22257705).

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

21080535 is a wasteful number, since it uses less digits than its factorization.

21080535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117 (or 110 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 21080535 is about 4591.3543753450. The cubic root of 21080535 is about 276.2446502243.

Adding to 21080535 its reverse (53508012), we get a palindrome (74588547).

The spelling of 21080535 in words is "twenty-one million, eighty thousand, five hundred thirty-five".