21585113 has 4 divisors (see below), whose sum is σ = 23547408. Its totient is φ = 19622820.

The previous prime is 21585107. The next prime is 21585127. The reversal of 21585113 is 31158512.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21585113 - 2¹⁰ = 21584089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21585133) 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 3 ways as a sum of consecutive naturals, for example, 981131 + ... + 981152.

It is an arithmetic number, because the mean of its divisors is an integer number (5886852).

Almost surely, 2^21585113 is an apocalyptic number.

It is an amenable number.

21585113 is a deficient number, since it is larger than the sum of its proper divisors (1962295).

21585113 is a wasteful number, since it uses less digits than its factorization.

21585113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1962294.

The product of its digits is 1200, while the sum is 26.

The square root of 21585113 is about 4645.9781531987. The cubic root of 21585113 is about 278.4313344485.

The spelling of 21585113 in words is "twenty-one million, five hundred eighty-five thousand, one hundred thirteen".