21240020204101 has 8 divisors (see below), whose sum is σ = 21264356456280. Its totient is φ = 21215688248832.

The previous prime is 21240020203999. The next prime is 21240020204149. The reversal of 21240020204101 is 10140202004212.

It can be written as a sum of positive squares in 4 ways, for example, as 13940134855201 + 7299885348900 = 3733649^2 + 2701830^2 .

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 21240020204101 - 2¹³ = 21240020195909 is a prime.

It is a super-2 number, since 2×21240020204101² (a number of 27 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 (21240020234101) 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, 8870301 + ... + 11007373.

It is an arithmetic number, because the mean of its divisors is an integer number (2658044557035).

Almost surely, 2^{21240020204101} is an apocalyptic number.

It is an amenable number.

21240020204101 is a deficient number, since it is larger than the sum of its proper divisors (24336252179).

21240020204101 is a wasteful number, since it uses less digits than its factorization.

21240020204101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2148455.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21240020204101 its reverse (10140202004212), we get a palindrome (31380222208313).

The spelling of 21240020204101 in words is "twenty-one trillion, two hundred forty billion, twenty million, two hundred four thousand, one hundred one".