21115085 has 8 divisors (see below), whose sum is σ = 25506816. Its totient is φ = 16779600.

The previous prime is 21115063. The next prime is 21115091. The reversal of 21115085 is 58051112.

21115085 is nontrivially palindromic in base 13.

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

It is not a de Polignac number, because 21115085 - 2¹² = 21110989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21115085.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13229 + ... + 14738.

It is an arithmetic number, because the mean of its divisors is an integer number (3188352).

Almost surely, 2^21115085 is an apocalyptic number.

It is an amenable number.

21115085 is a deficient number, since it is larger than the sum of its proper divisors (4391731).

21115085 is a wasteful number, since it uses less digits than its factorization.

21115085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28123.

The product of its (nonzero) digits is 400, while the sum is 23.

The square root of 21115085 is about 4595.1153413163. The cubic root of 21115085 is about 276.3954851567.

Adding to 21115085 its reverse (58051112), we get a palindrome (79166197).

The spelling of 21115085 in words is "twenty-one million, one hundred fifteen thousand, eighty-five".