21123541111241 has 4 divisors (see below), whose sum is σ = 21317335066500. Its totient is φ = 20929747155984.

The previous prime is 21123541111219. The next prime is 21123541111259. The reversal of 21123541111241 is 14211114532112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13813331123641 + 7310209987600 = 3716629^2 + 2703740^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123541111241 is a prime.

It is a super-2 number, since 2×21123541111241² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21123541111271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96896977466 + ... + 96896977683.

It is an arithmetic number, because the mean of its divisors is an integer number (5329333766625).

Almost surely, 2^{21123541111241} is an apocalyptic number.

It is an amenable number.

21123541111241 is a deficient number, since it is larger than the sum of its proper divisors (193793955259).

21123541111241 is a wasteful number, since it uses less digits than its factorization.

21123541111241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193793955258.

The product of its digits is 1920, while the sum is 29.

Adding to 21123541111241 its reverse (14211114532112), we get a palindrome (35334655643353).

The spelling of 21123541111241 in words is "twenty-one trillion, one hundred twenty-three billion, five hundred forty-one million, one hundred eleven thousand, two hundred forty-one".