21318108 has 24 divisors (see below), whose sum is σ = 56848512. Its totient is φ = 6090864.

The previous prime is 21318091. The next prime is 21318109. The reversal of 21318108 is 80181312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21318109) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126810 + ... + 126977.

It is an arithmetic number, because the mean of its divisors is an integer number (2368688).

Almost surely, 2^21318108 is an apocalyptic number.

21318108 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21318108 is an abundant number, since it is smaller than the sum of its proper divisors (35530404).

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

21318108 is a wasteful number, since it uses less digits than its factorization.

21318108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253801 (or 253799 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 24.

The square root of 21318108 is about 4617.1536686578. The cubic root of 21318108 is about 277.2785149346.

The spelling of 21318108 in words is "twenty-one million, three hundred eighteen thousand, one hundred eight".