21313085 has 4 divisors (see below), whose sum is σ = 25575708. Its totient is φ = 17050464.

The previous prime is 21313063. The next prime is 21313091. The reversal of 21313085 is 58031312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14417209 + 6895876 = 3797^2 + 2626^2 .

It is a cyclic number.

It is not a de Polignac number, because 21313085 - 2⁶ = 21313021 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 21313085.

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 3 ways as a sum of consecutive naturals, for example, 2131304 + ... + 2131313.

It is an arithmetic number, because the mean of its divisors is an integer number (6393927).

Almost surely, 2^21313085 is an apocalyptic number.

It is an amenable number.

21313085 is a deficient number, since it is larger than the sum of its proper divisors (4262623).

21313085 is an equidigital number, since it uses as much as digits as its factorization.

21313085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4262622.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21313085 is about 4616.6096867723. The cubic root of 21313085 is about 277.2567356506.

Adding to 21313085 its reverse (58031312), we get a palindrome (79344397).

The spelling of 21313085 in words is "twenty-one million, three hundred thirteen thousand, eighty-five".