21018112 has 20 divisors (see below), whose sum is σ = 41996196. Its totient is φ = 10508800.

The previous prime is 21018097. The next prime is 21018133. The reversal of 21018112 is 21181012.

It is a super-2 number, since 2×21018112² = 883522064089088, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20014 + ... + 21037.

Almost surely, 2^21018112 is an apocalyptic number.

It is an amenable number.

21018112 is a deficient number, since it is larger than the sum of its proper divisors (20978084).

21018112 is an frugal number, since it uses more digits than its factorization.

21018112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41069 (or 41053 counting only the distinct ones).

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

The square root of 21018112 is about 4584.5514502512. The cubic root of 21018112 is about 275.9717117265.

Adding to 21018112 its reverse (21181012), we get a palindrome (42199124).

The spelling of 21018112 in words is "twenty-one million, eighteen thousand, one hundred twelve".