21838085 has 4 divisors (see below), whose sum is σ = 26205708. Its totient is φ = 17470464.

The previous prime is 21838057. The next prime is 21838099. The reversal of 21838085 is 58083812.

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 8014561 + 13823524 = 2831^2 + 3718^2 .

It is a cyclic number.

It is not a de Polignac number, because 21838085 - 2⁶ = 21838021 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 (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2183804 + ... + 2183813.

It is an arithmetic number, because the mean of its divisors is an integer number (6551427).

Almost surely, 2^21838085 is an apocalyptic number.

It is an amenable number.

21838085 is a deficient number, since it is larger than the sum of its proper divisors (4367623).

21838085 is an equidigital number, since it uses as much as digits as its factorization.

21838085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4367622.

The product of its (nonzero) digits is 15360, while the sum is 35.

The square root of 21838085 is about 4673.1236876419. The cubic root of 21838085 is about 279.5148273150.

The spelling of 21838085 in words is "twenty-one million, eight hundred thirty-eight thousand, eighty-five".