21043111155201 has 72 divisors (see below), whose sum is σ = 32943387282624. Its totient is φ = 12936517102080.

The previous prime is 21043111155163. The next prime is 21043111155221. The reversal of 21043111155201 is 10255111134012.

21043111155201 is a `hidden beast` number, since 2 + 1 + 0 + 431 + 11 + 15 + 5 + 201 = 666.

It is not a de Polignac number, because 21043111155201 - 2¹⁵ = 21043111122433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21043111155221) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 100114146 + ... + 100324116.

It is an arithmetic number, because the mean of its divisors is an integer number (457547045592).

Almost surely, 2^{21043111155201} is an apocalyptic number.

It is an amenable number.

21043111155201 is a deficient number, since it is larger than the sum of its proper divisors (11900276127423).

21043111155201 is a wasteful number, since it uses less digits than its factorization.

21043111155201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210791 (or 210771 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 27.

Adding to 21043111155201 its reverse (10255111134012), we get a palindrome (31298222289213).

The spelling of 21043111155201 in words is "twenty-one trillion, forty-three billion, one hundred eleven million, one hundred fifty-five thousand, two hundred one".