21361606 has 16 divisors (see below), whose sum is σ = 36771840. Its totient is φ = 9117000.

The previous prime is 21361591. The next prime is 21361609. The reversal of 21361606 is 60616312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21361609) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 475 + ... + 6553.

It is an arithmetic number, because the mean of its divisors is an integer number (2298240).

Almost surely, 2^21361606 is an apocalyptic number.

21361606 is a deficient number, since it is larger than the sum of its proper divisors (15410234).

21361606 is a wasteful number, since it uses less digits than its factorization.

21361606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6339.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 21361606 is about 4621.8617460932. The cubic root of 21361606 is about 277.4669754818.

Adding to 21361606 its reverse (60616312), we get a palindrome (81977918).

The spelling of 21361606 in words is "twenty-one million, three hundred sixty-one thousand, six hundred six".