216181831058381 has 2 divisors, whose sum is σ = 216181831058382. Its totient is φ = 216181831058380.

The previous prime is 216181831058279. The next prime is 216181831058383. The reversal of 216181831058381 is 183850138181612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 215075423702500 + 1106407355881 = 14665450^2 + 1051859^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216181831058381 is a prime.

It is a super-2 number, since 2×216181831058381² (a number of 29 digits) contains 22 as substring.

Together with 216181831058383, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216181831058383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108090915529190 + 108090915529191.

It is an arithmetic number, because the mean of its divisors is an integer number (108090915529191).

Almost surely, 2^{216181831058381} is an apocalyptic number.

It is an amenable number.

216181831058381 is a deficient number, since it is larger than the sum of its proper divisors (1).

216181831058381 is an equidigital number, since it uses as much as digits as its factorization.

216181831058381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2211840, while the sum is 56.

The spelling of 216181831058381 in words is "two hundred sixteen trillion, one hundred eighty-one billion, eight hundred thirty-one million, fifty-eight thousand, three hundred eighty-one".