21135318 has 32 divisors (see below), whose sum is σ = 45191520. Its totient is φ = 6566400.

The previous prime is 21135311. The next prime is 21135329. The reversal of 21135318 is 81353112.

It is a super-2 number, since 2×21135318² = 893403333922248, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21135311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10168 + ... + 12068.

It is an arithmetic number, because the mean of its divisors is an integer number (1412235).

Almost surely, 2^21135318 is an apocalyptic number.

21135318 is an abundant number, since it is smaller than the sum of its proper divisors (24056202).

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

21135318 is a wasteful number, since it uses less digits than its factorization.

21135318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2032.

The product of its digits is 720, while the sum is 24.

The square root of 21135318 is about 4597.3163911134. The cubic root of 21135318 is about 276.4837399845.

The spelling of 21135318 in words is "twenty-one million, one hundred thirty-five thousand, three hundred eighteen".