21819173710387 has 2 divisors, whose sum is σ = 21819173710388. Its totient is φ = 21819173710386.

The previous prime is 21819173710289. The next prime is 21819173710391. The reversal of 21819173710387 is 78301737191812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21819173710387 - 2¹⁵ = 21819173677619 is a prime.

It is not a weakly prime, because it can be changed into another prime (21819173810387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10909586855193 + 10909586855194.

It is an arithmetic number, because the mean of its divisors is an integer number (10909586855194).

Almost surely, 2^{21819173710387} is an apocalyptic number.

21819173710387 is a deficient number, since it is larger than the sum of its proper divisors (1).

21819173710387 is an equidigital number, since it uses as much as digits as its factorization.

21819173710387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3556224, while the sum is 58.

The spelling of 21819173710387 in words is "twenty-one trillion, eight hundred nineteen billion, one hundred seventy-three million, seven hundred ten thousand, three hundred eighty-seven".