3666673340021 has 2 divisors, whose sum is σ = 3666673340022. Its totient is φ = 3666673340020.

The previous prime is 3666673339951. The next prime is 3666673340039. The reversal of 3666673340021 is 1200433766663.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2316164391025 + 1350508948996 = 1521895^2 + 1162114^2 .

It is a cyclic number.

It is not a de Polignac number, because 3666673340021 - 2¹⁴ = 3666673323637 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3666673340081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1833336670010 + 1833336670011.

It is an arithmetic number, because the mean of its divisors is an integer number (1833336670011).

Almost surely, 2^{3666673340021} is an apocalyptic number.

It is an amenable number.

3666673340021 is a deficient number, since it is larger than the sum of its proper divisors (1).

3666673340021 is an equidigital number, since it uses as much as digits as its factorization.

3666673340021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1959552, while the sum is 47.

The spelling of 3666673340021 in words is "three trillion, six hundred sixty-six billion, six hundred seventy-three million, three hundred forty thousand, twenty-one".