21711085 has 8 divisors (see below), whose sum is σ = 28421856. Its totient is φ = 15789840.

The previous prime is 21711083. The next prime is 21711097. The reversal of 21711085 is 58011712.

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

It is not a de Polignac number, because 21711085 - 2¹ = 21711083 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21711083) 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 7 ways as a sum of consecutive naturals, for example, 197319 + ... + 197428.

It is an arithmetic number, because the mean of its divisors is an integer number (3552732).

Almost surely, 2^21711085 is an apocalyptic number.

It is an amenable number.

21711085 is a deficient number, since it is larger than the sum of its proper divisors (6710771).

21711085 is a wasteful number, since it uses less digits than its factorization.

21711085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394763.

The product of its (nonzero) digits is 560, while the sum is 25.

The square root of 21711085 is about 4659.5155327566. The cubic root of 21711085 is about 278.9719314183.

Adding to 21711085 its reverse (58011712), we get a palindrome (79722797).

It can be divided in two parts, 2171 and 1085, that multiplied together give a triangular number (2355535 = T₂₁₇₀).

The spelling of 21711085 in words is "twenty-one million, seven hundred eleven thousand, eighty-five".