21818196 has 36 divisors (see below), whose sum is σ = 55348384. Its totient is φ = 7246800.

The previous prime is 21818171. The next prime is 21818201. The reversal of 21818196 is 69181812.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21818196.

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 11 ways as a sum of consecutive naturals, for example, 11001 + ... + 12831.

Almost surely, 2^21818196 is an apocalyptic number.

It is an amenable number.

21818196 is an abundant number, since it is smaller than the sum of its proper divisors (33530188).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21818196 is a wasteful number, since it uses less digits than its factorization.

21818196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2172 (or 2167 counting only the distinct ones).

The product of its digits is 6912, while the sum is 36.

The square root of 21818196 is about 4670.9951830418. The cubic root of 21818196 is about 279.4299456514.

The spelling of 21818196 in words is "twenty-one million, eight hundred eighteen thousand, one hundred ninety-six".