1666335947737 has 2 divisors, whose sum is σ = 1666335947738. Its totient is φ = 1666335947736.

The previous prime is 1666335947707. The next prime is 1666335947777. The reversal of 1666335947737 is 7377495336661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1655658652176 + 10677295561 = 1286724^2 + 103331^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666335947737 is a prime.

It is a super-3 number, since 3×1666335947737³ (a number of 38 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1666335947707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833167973868 + 833167973869.

It is an arithmetic number, because the mean of its divisors is an integer number (833167973869).

Almost surely, 2^{1666335947737} is an apocalyptic number.

It is an amenable number.

1666335947737 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666335947737 is an equidigital number, since it uses as much as digits as its factorization.

1666335947737 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360067680, while the sum is 67.

The spelling of 1666335947737 in words is "one trillion, six hundred sixty-six billion, three hundred thirty-five million, nine hundred forty-seven thousand, seven hundred thirty-seven".