21213118 has 8 divisors (see below), whose sum is σ = 31868712. Its totient is φ = 10590216.

The previous prime is 21213109. The next prime is 21213119. The reversal of 21213118 is 81131212.

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 = 21213095 and 21213104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213119) 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, 6480 + ... + 9187.

It is an arithmetic number, because the mean of its divisors is an integer number (3983589).

Almost surely, 2^21213118 is an apocalyptic number.

21213118 is a deficient number, since it is larger than the sum of its proper divisors (10655594).

21213118 is a wasteful number, since it uses less digits than its factorization.

21213118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16346.

The product of its digits is 96, while the sum is 19.

The square root of 21213118 is about 4605.7700767624. The cubic root of 21213118 is about 276.8225740190.

The spelling of 21213118 in words is "twenty-one million, two hundred thirteen thousand, one hundred eighteen".