1216571139841 has 2 divisors, whose sum is σ = 1216571139842. Its totient is φ = 1216571139840.

The previous prime is 1216571139803. The next prime is 1216571139857. The reversal of 1216571139841 is 1489311756121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1154335360000 + 62235779841 = 1074400^2 + 249471^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1216571139841 is a prime.

It is not a weakly prime, because it can be changed into another prime (1216571239841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608285569920 + 608285569921.

It is an arithmetic number, because the mean of its divisors is an integer number (608285569921).

Almost surely, 2^{1216571139841} is an apocalyptic number.

It is an amenable number.

1216571139841 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216571139841 is an equidigital number, since it uses as much as digits as its factorization.

1216571139841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 49.

The spelling of 1216571139841 in words is "one trillion, two hundred sixteen billion, five hundred seventy-one million, one hundred thirty-nine thousand, eight hundred forty-one".