1666334694877 has 2 divisors, whose sum is σ = 1666334694878. Its totient is φ = 1666334694876.

The previous prime is 1666334694853. The next prime is 1666334694889. The reversal of 1666334694877 is 7784964336661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1073698005636 + 592636689241 = 1036194^2 + 769829^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666334694877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666334694847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833167347438 + 833167347439.

It is an arithmetic number, because the mean of its divisors is an integer number (833167347439).

Almost surely, 2^{1666334694877} is an apocalyptic number.

It is an amenable number.

1666334694877 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666334694877 is an equidigital number, since it uses as much as digits as its factorization.

1666334694877 is an evil number, because the sum of its binary digits is even.

The product of its digits is 658409472, while the sum is 70.

The spelling of 1666334694877 in words is "one trillion, six hundred sixty-six billion, three hundred thirty-four million, six hundred ninety-four thousand, eight hundred seventy-seven".