21331606 has 8 divisors (see below), whose sum is σ = 32158800. Its totient is φ = 10612008.

The previous prime is 21331589. The next prime is 21331621. The reversal of 21331606 is 60613312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26401 + ... + 27196.

It is an arithmetic number, because the mean of its divisors is an integer number (4019850).

Almost surely, 2^21331606 is an apocalyptic number.

21331606 is a deficient number, since it is larger than the sum of its proper divisors (10827194).

21331606 is a wasteful number, since it uses less digits than its factorization.

21331606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53798.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 21331606 is about 4618.6151604133. The cubic root of 21331606 is about 277.3370241255.

Adding to 21331606 its reverse (60613312), we get a palindrome (81944918).

The spelling of 21331606 in words is "twenty-one million, three hundred thirty-one thousand, six hundred six".