21112018 has 8 divisors (see below), whose sum is σ = 31734000. Its totient is φ = 10534020.

The previous prime is 21112009. The next prime is 21112019. The reversal of 21112018 is 81021112.

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 = 21111992 and 21112010.

It is not an unprimeable number, because it can be changed into a prime (21112019) 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, 9768 + ... + 11731.

It is an arithmetic number, because the mean of its divisors is an integer number (3966750).

Almost surely, 2^21112018 is an apocalyptic number.

21112018 is a deficient number, since it is larger than the sum of its proper divisors (10621982).

21112018 is a wasteful number, since it uses less digits than its factorization.

21112018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21992.

The product of its (nonzero) digits is 32, while the sum is 16.

The square root of 21112018 is about 4594.7816052561. The cubic root of 21112018 is about 276.3821022127.

It can be divided in two parts, 2111201 and 8, that added together give a square (2111209 = 1453²).

The spelling of 21112018 in words is "twenty-one million, one hundred twelve thousand, eighteen".