21320131606 has 4 divisors (see below), whose sum is σ = 31980197412. Its totient is φ = 10660065802.

The previous prime is 21320131577. The next prime is 21320131619. The reversal of 21320131606 is 60613102312.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5330032900 + ... + 5330032903.

It is an arithmetic number, because the mean of its divisors is an integer number (7995049353).

Almost surely, 2^21320131606 is an apocalyptic number.

21320131606 is a deficient number, since it is larger than the sum of its proper divisors (10660065806).

21320131606 is a wasteful number, since it uses less digits than its factorization.

21320131606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10660065805.

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

Adding to 21320131606 its reverse (60613102312), we get a palindrome (81933233918).

The spelling of 21320131606 in words is "twenty-one billion, three hundred twenty million, one hundred thirty-one thousand, six hundred six".