21551013305111 has 2 divisors, whose sum is σ = 21551013305112. Its totient is φ = 21551013305110.

The previous prime is 21551013305089. The next prime is 21551013305191. The reversal of 21551013305111 is 11150331015512.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21551013305111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21551013305191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10775506652555 + 10775506652556.

It is an arithmetic number, because the mean of its divisors is an integer number (10775506652556).

Almost surely, 2^{21551013305111} is an apocalyptic number.

21551013305111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21551013305111 is an equidigital number, since it uses as much as digits as its factorization.

21551013305111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2250, while the sum is 29.

The spelling of 21551013305111 in words is "twenty-one trillion, five hundred fifty-one billion, thirteen million, three hundred five thousand, one hundred eleven".