21166221202519 has 2 divisors, whose sum is σ = 21166221202520. Its totient is φ = 21166221202518.

The previous prime is 21166221202517. The next prime is 21166221202561. The reversal of 21166221202519 is 91520212266112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21166221202519 - 2¹ = 21166221202517 is a prime.

It is a super-2 number, since 2×21166221202519² (a number of 27 digits) contains 22 as substring.

Together with 21166221202517, 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 (21166221202517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10583110601259 + 10583110601260.

It is an arithmetic number, because the mean of its divisors is an integer number (10583110601260).

Almost surely, 2^{21166221202519} is an apocalyptic number.

21166221202519 is a deficient number, since it is larger than the sum of its proper divisors (1).

21166221202519 is an equidigital number, since it uses as much as digits as its factorization.

21166221202519 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 40.

The spelling of 21166221202519 in words is "twenty-one trillion, one hundred sixty-six billion, two hundred twenty-one million, two hundred two thousand, five hundred nineteen".