21530541134149 has 2 divisors, whose sum is σ = 21530541134150. Its totient is φ = 21530541134148.

The previous prime is 21530541134147. The next prime is 21530541134189. The reversal of 21530541134149 is 94143114503512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11603901602500 + 9926639531649 = 3406450^2 + 3150657^2 .

It is a cyclic number.

It is not a de Polignac number, because 21530541134149 - 2¹ = 21530541134147 is a prime.

Together with 21530541134147, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21530541134147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10765270567074 + 10765270567075.

It is an arithmetic number, because the mean of its divisors is an integer number (10765270567075).

Almost surely, 2^{21530541134149} is an apocalyptic number.

It is an amenable number.

21530541134149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21530541134149 is an equidigital number, since it uses as much as digits as its factorization.

21530541134149 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 259200, while the sum is 43.

The spelling of 21530541134149 in words is "twenty-one trillion, five hundred thirty billion, five hundred forty-one million, one hundred thirty-four thousand, one hundred forty-nine".