21112006 has 4 divisors (see below), whose sum is σ = 31668012. Its totient is φ = 10556002.

The previous prime is 21111991. The next prime is 21112009. The reversal of 21112006 is 60021112.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5278000 + ... + 5278003.

It is an arithmetic number, because the mean of its divisors is an integer number (7917003).

Almost surely, 2^21112006 is an apocalyptic number.

21112006 is a deficient number, since it is larger than the sum of its proper divisors (10556006).

21112006 is a wasteful number, since it uses less digits than its factorization.

21112006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10556005.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 21112006 is about 4594.7802994267. The cubic root of 21112006 is about 276.3820498478.

Adding to 21112006 its reverse (60021112), we get a palindrome (81133118).

The spelling of 21112006 in words is "twenty-one million, one hundred twelve thousand, six".