21211202001005 has 16 divisors (see below), whose sum is σ = 26950891011120. Its totient is φ = 15970676401152.

The previous prime is 21211202000981. The next prime is 21211202001043. The reversal of 21211202001005 is 50010020211212.

It can be written as a sum of positive squares in 8 ways, for example, as 2798975844196 + 18412226156809 = 1673014^2 + 4290947^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211202001005 - 2³² = 21206907033709 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12672431 + ... + 14248259.

It is an arithmetic number, because the mean of its divisors is an integer number (1684430688195).

Almost surely, 2^{21211202001005} is an apocalyptic number.

It is an amenable number.

21211202001005 is a deficient number, since it is larger than the sum of its proper divisors (5739689010115).

21211202001005 is a wasteful number, since it uses less digits than its factorization.

21211202001005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1734208.

The product of its (nonzero) digits is 80, while the sum is 17.

Adding to 21211202001005 its reverse (50010020211212), we get a palindrome (71221222212217).

The spelling of 21211202001005 in words is "twenty-one trillion, two hundred eleven billion, two hundred two million, one thousand, five".