21116575 has 12 divisors (see below), whose sum is σ = 26446968. Its totient is φ = 16724000.

The previous prime is 21116561. The next prime is 21116587. The reversal of 21116575 is 57561112.

It is not a de Polignac number, because 21116575 - 2⁹ = 21116063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 1657 + ... + 6706.

It is an arithmetic number, because the mean of its divisors is an integer number (2203914).

Almost surely, 2^21116575 is an apocalyptic number.

21116575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21116575 is a deficient number, since it is larger than the sum of its proper divisors (5330393).

21116575 is a wasteful number, since it uses less digits than its factorization.

21116575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8474 (or 8469 counting only the distinct ones).

The product of its digits is 2100, while the sum is 28.

The square root of 21116575 is about 4595.2774671395. The cubic root of 21116575 is about 276.4019863475.

Adding to 21116575 its reverse (57561112), we get a palindrome (78677687).

The spelling of 21116575 in words is "twenty-one million, one hundred sixteen thousand, five hundred seventy-five".