21138118 has 8 divisors (see below), whose sum is σ = 31727160. Its totient is φ = 10562400.

The previous prime is 21138113. The next prime is 21138121. The reversal of 21138118 is 81183112.

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

It is a junction number, because it is equal to n+sod(n) for n = 21138092 and 21138101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21138113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3193 + ... + 7243.

It is an arithmetic number, because the mean of its divisors is an integer number (3965895).

Almost surely, 2^21138118 is an apocalyptic number.

21138118 is a deficient number, since it is larger than the sum of its proper divisors (10589042).

21138118 is a wasteful number, since it uses less digits than its factorization.

21138118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6662.

The product of its digits is 384, while the sum is 25.

The square root of 21138118 is about 4597.6209065124. The cubic root of 21138118 is about 276.4959489371.

The spelling of 21138118 in words is "twenty-one million, one hundred thirty-eight thousand, one hundred eighteen".