21162205 has 8 divisors (see below), whose sum is σ = 25452504. Its totient is φ = 16891200.

The previous prime is 21162203. The next prime is 21162217. The reversal of 21162205 is 50226112.

It can be written as a sum of positive squares in 4 ways, for example, as 1898884 + 19263321 = 1378^2 + 4389^2 .

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

It is not a de Polignac number, because 21162205 - 2¹ = 21162203 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 (21162203) 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, 2286 + ... + 6895.

It is an arithmetic number, because the mean of its divisors is an integer number (3181563).

Almost surely, 2^21162205 is an apocalyptic number.

It is an amenable number.

21162205 is a deficient number, since it is larger than the sum of its proper divisors (4290299).

21162205 is an equidigital number, since it uses as much as digits as its factorization.

21162205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9647.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21162205 is about 4600.2396676695. The cubic root of 21162205 is about 276.6009319483.

Adding to 21162205 its reverse (50226112), we get a palindrome (71388317).

The spelling of 21162205 in words is "twenty-one million, one hundred sixty-two thousand, two hundred five".