217812142155541 has 2 divisors, whose sum is σ = 217812142155542. Its totient is φ = 217812142155540.

The previous prime is 217812142155521. The next prime is 217812142155551. The reversal of 217812142155541 is 145551241218712.

217812142155541 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 170934444156100 + 46877697999441 = 13074190^2 + 6846729^2 .

It is a cyclic number.

It is not a de Polignac number, because 217812142155541 - 2¹³ = 217812142147349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217812142155521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108906071077770 + 108906071077771.

It is an arithmetic number, because the mean of its divisors is an integer number (108906071077771).

Almost surely, 2^{217812142155541} is an apocalyptic number.

It is an amenable number.

217812142155541 is a deficient number, since it is larger than the sum of its proper divisors (1).

217812142155541 is an equidigital number, since it uses as much as digits as its factorization.

217812142155541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 896000, while the sum is 49.

The spelling of 217812142155541 in words is "two hundred seventeen trillion, eight hundred twelve billion, one hundred forty-two million, one hundred fifty-five thousand, five hundred forty-one".