21818104 has 32 divisors (see below), whose sum is σ = 51004800. Its totient is φ = 8500320.

The previous prime is 21818077. The next prime is 21818117. The reversal of 21818104 is 40181812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17094 + ... + 18325.

It is an arithmetic number, because the mean of its divisors is an integer number (1593900).

Almost surely, 2^21818104 is an apocalyptic number.

It is an amenable number.

21818104 is an abundant number, since it is smaller than the sum of its proper divisors (29186696).

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

21818104 is a wasteful number, since it uses less digits than its factorization.

21818104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35443 (or 35439 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 25.

The square root of 21818104 is about 4670.9853350230. The cubic root of 21818104 is about 279.4295528967.

Adding to 21818104 its reverse (40181812), we get a palindrome (61999916).

The spelling of 21818104 in words is "twenty-one million, eight hundred eighteen thousand, one hundred four".