21640352005 has 8 divisors (see below), whose sum is σ = 27335181600. Its totient is φ = 16401108816.

The previous prime is 21640352003. The next prime is 21640352021. The reversal of 21640352005 is 50025304612.

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

It is a cyclic number.

It is not a de Polignac number, because 21640352005 - 2¹ = 21640352003 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21640352003) 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, 113896495 + ... + 113896684.

It is an arithmetic number, because the mean of its divisors is an integer number (3416897700).

Almost surely, 2^21640352005 is an apocalyptic number.

It is an amenable number.

21640352005 is a deficient number, since it is larger than the sum of its proper divisors (5694829595).

21640352005 is a wasteful number, since it uses less digits than its factorization.

21640352005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227793203.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 21640352005 its reverse (50025304612), we get a palindrome (71665656617).

The spelling of 21640352005 in words is "twenty-one billion, six hundred forty million, three hundred fifty-two thousand, five".