21261161112011 has 8 divisors (see below), whose sum is σ = 21784423155264. Its totient is φ = 20738122742080.

The previous prime is 21261161111989. The next prime is 21261161112029. The reversal of 21261161112011 is 11021116116212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21261161112011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21261161112031) 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, 55725875 + ... + 56106108.

It is an arithmetic number, because the mean of its divisors is an integer number (2723052894408).

Almost surely, 2^{21261161112011} is an apocalyptic number.

21261161112011 is a deficient number, since it is larger than the sum of its proper divisors (523262043253).

21261161112011 is a wasteful number, since it uses less digits than its factorization.

21261161112011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111836661.

The product of its (nonzero) digits is 288, while the sum is 26.

Adding to 21261161112011 its reverse (11021116116212), we get a palindrome (32282277228223).

The spelling of 21261161112011 in words is "twenty-one trillion, two hundred sixty-one billion, one hundred sixty-one million, one hundred twelve thousand, eleven".