21811112 has 8 divisors (see below), whose sum is σ = 40895850. Its totient is φ = 10905552.

The previous prime is 21811109. The next prime is 21811117. The reversal of 21811112 is 21111812.

It can be written as a sum of positive squares in only one way, i.e., 19945156 + 1865956 = 4466^2 + 1366^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21811117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1363187 + ... + 1363202.

Almost surely, 2^21811112 is an apocalyptic number.

It is an amenable number.

21811112 is a deficient number, since it is larger than the sum of its proper divisors (19084738).

21811112 is a wasteful number, since it uses less digits than its factorization.

21811112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2726395 (or 2726391 counting only the distinct ones).

The product of its digits is 32, while the sum is 17.

The square root of 21811112 is about 4670.2368248302. The cubic root of 21811112 is about 279.3997003153.

Adding to 21811112 its reverse (21111812), we get a palindrome (42922924).

The spelling of 21811112 in words is "twenty-one million, eight hundred eleven thousand, one hundred twelve".