21161105061211 has 8 divisors (see below), whose sum is σ = 21176343777600. Its totient is φ = 21145867249800.

The previous prime is 21161105061181. The next prime is 21161105061221. The reversal of 21161105061211 is 11216050116112.

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 21161105061211 - 2⁹ = 21161105060699 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21161105061211.

It is not an unprimeable number, because it can be changed into a prime (21161105061221) 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, 50662620 + ... + 51078598.

It is an arithmetic number, because the mean of its divisors is an integer number (2647042972200).

Almost surely, 2^{21161105061211} is an apocalyptic number.

21161105061211 is a deficient number, since it is larger than the sum of its proper divisors (15238716389).

21161105061211 is a wasteful number, since it uses less digits than its factorization.

21161105061211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452489.

The product of its (nonzero) digits is 720, while the sum is 28.

Adding to 21161105061211 its reverse (11216050116112), we get a palindrome (32377155177323).

The spelling of 21161105061211 in words is "twenty-one trillion, one hundred sixty-one billion, one hundred five million, sixty-one thousand, two hundred eleven".