21808162 has 8 divisors (see below), whose sum is σ = 34434000. Its totient is φ = 10330164.

The previous prime is 21808153. The next prime is 21808177. The reversal of 21808162 is 26180812.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21808162.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 286912 + ... + 286987.

It is an arithmetic number, because the mean of its divisors is an integer number (4304250).

Almost surely, 2^21808162 is an apocalyptic number.

21808162 is a deficient number, since it is larger than the sum of its proper divisors (12625838).

21808162 is a wasteful number, since it uses less digits than its factorization.

21808162 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 573920.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 21808162 is about 4669.9209843422. The cubic root of 21808162 is about 279.3871032764.

Adding to 21808162 its reverse (26180812), we get a palindrome (47988974).

The spelling of 21808162 in words is "twenty-one million, eight hundred eight thousand, one hundred sixty-two".