1720661183977 has 2 divisors, whose sum is σ = 1720661183978. Its totient is φ = 1720661183976.

The previous prime is 1720661183963. The next prime is 1720661184019. The reversal of 1720661183977 is 7793811660271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1261351363801 + 459309820176 = 1123099^2 + 677724^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1720661183977 is a prime.

It is not a weakly prime, because it can be changed into another prime (1720661183947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860330591988 + 860330591989.

It is an arithmetic number, because the mean of its divisors is an integer number (860330591989).

Almost surely, 2^{1720661183977} is an apocalyptic number.

It is an amenable number.

1720661183977 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720661183977 is an equidigital number, since it uses as much as digits as its factorization.

1720661183977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5334336, while the sum is 58.

The spelling of 1720661183977 in words is "one trillion, seven hundred twenty billion, six hundred sixty-one million, one hundred eighty-three thousand, nine hundred seventy-seven".