21660561143219 has 2 divisors, whose sum is σ = 21660561143220. Its totient is φ = 21660561143218.

The previous prime is 21660561143129. The next prime is 21660561143257. The reversal of 21660561143219 is 91234116506612.

Together with previous prime (21660561143129) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21660561143219 - 2³² = 21656266175923 is a prime.

It is a super-2 number, since 2×21660561143219² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21660561143269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10830280571609 + 10830280571610.

It is an arithmetic number, because the mean of its divisors is an integer number (10830280571610).

Almost surely, 2^{21660561143219} is an apocalyptic number.

21660561143219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21660561143219 is an equidigital number, since it uses as much as digits as its factorization.

21660561143219 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 466560, while the sum is 47.

The spelling of 21660561143219 in words is "twenty-one trillion, six hundred sixty billion, five hundred sixty-one million, one hundred forty-three thousand, two hundred nineteen".