21201210005 has 8 divisors (see below), whose sum is σ = 25513526232. Its totient is φ = 16912918528.

The previous prime is 21201209993. The next prime is 21201210007. The reversal of 21201210005 is 50001210212.

It can be written as a sum of positive squares in 4 ways, for example, as 1414286449 + 19786923556 = 37607^2 + 140666^2 .

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 21201210005 - 2²² = 21197015701 is a prime.

It is a super-2 number, since 2×21201210005² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201210007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6004244 + ... + 6007773.

It is an arithmetic number, because the mean of its divisors is an integer number (3189190779).

Almost surely, 2^21201210005 is an apocalyptic number.

It is an amenable number.

21201210005 is a deficient number, since it is larger than the sum of its proper divisors (4312316227).

21201210005 is a wasteful number, since it uses less digits than its factorization.

21201210005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12012375.

The product of its (nonzero) digits is 40, while the sum is 14.

Adding to 21201210005 its reverse (50001210212), we get a palindrome (71202420217).

The spelling of 21201210005 in words is "twenty-one billion, two hundred one million, two hundred ten thousand, five".