1216961719997 has 2 divisors, whose sum is σ = 1216961719998. Its totient is φ = 1216961719996.

The previous prime is 1216961719949. The next prime is 1216961720081. The reversal of 1216961719997 is 7999171696121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1216920065881 + 41654116 = 1103141^2 + 6454^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216961719997 - 2⁸ = 1216961719741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1216961719097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608480859998 + 608480859999.

It is an arithmetic number, because the mean of its divisors is an integer number (608480859999).

Almost surely, 2^{1216961719997} is an apocalyptic number.

It is an amenable number.

1216961719997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216961719997 is an equidigital number, since it uses as much as digits as its factorization.

1216961719997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23147208, while the sum is 68.

The spelling of 1216961719997 in words is "one trillion, two hundred sixteen billion, nine hundred sixty-one million, seven hundred nineteen thousand, nine hundred ninety-seven".