21112461187481 has 4 divisors (see below), whose sum is σ = 21266566743732. Its totient is φ = 20958355631232.

The previous prime is 21112461187471. The next prime is 21112461187513. The reversal of 21112461187481 is 18478116421112.

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 18086809673881 + 3025651513600 = 4252859^2 + 1739440^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112461187481 is a prime.

It is a super-2 number, since 2×21112461187481² (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 (21112461187451) 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, 77052777920 + ... + 77052778193.

It is an arithmetic number, because the mean of its divisors is an integer number (5316641685933).

Almost surely, 2^{21112461187481} is an apocalyptic number.

It is an amenable number.

21112461187481 is a deficient number, since it is larger than the sum of its proper divisors (154105556251).

21112461187481 is a wasteful number, since it uses less digits than its factorization.

21112461187481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154105556250.

The product of its digits is 172032, while the sum is 47.

The spelling of 21112461187481 in words is "twenty-one trillion, one hundred twelve billion, four hundred sixty-one million, one hundred eighty-seven thousand, four hundred eighty-one".