21111066 has 24 divisors (see below), whose sum is σ = 46605780. Its totient is φ = 6903936.

The previous prime is 21111061. The next prime is 21111073. The reversal of 21111066 is 66011112.

It can be written as a sum of positive squares in 2 ways, for example, as 17816841 + 3294225 = 4221^2 + 1815^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21111061) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10111 + ... + 12018.

Almost surely, 2^21111066 is an apocalyptic number.

21111066 is an abundant number, since it is smaller than the sum of its proper divisors (25494714).

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

21111066 is a wasteful number, since it uses less digits than its factorization.

21111066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22190 (or 22187 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 21111066 is about 4594.6780083048. The cubic root of 21111066 is about 276.3779478694.

Adding to 21111066 its reverse (66011112), we get a palindrome (87122178).

It can be divided in two parts, 2111106 and 6, that added together give a palindrome (2111112).

The spelling of 21111066 in words is "twenty-one million, one hundred eleven thousand, sixty-six".