21010218 has 8 divisors (see below), whose sum is σ = 42020448. Its totient is φ = 7003404.

The previous prime is 21010217. The next prime is 21010229. The reversal of 21010218 is 81201012.

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

21010218 is an admirable number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21010197 and 21010206.

It is not an unprimeable number, because it can be changed into a prime (21010217) 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, 1750846 + ... + 1750857.

It is an arithmetic number, because the mean of its divisors is an integer number (5252556).

Almost surely, 2^21010218 is an apocalyptic number.

21010218 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21010218 is a wasteful number, since it uses less digits than its factorization.

21010218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3501708.

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 21010218 is about 4583.6904345734. The cubic root of 21010218 is about 275.9371575051.

The spelling of 21010218 in words is "twenty-one million, ten thousand, two hundred eighteen".