1606436043661 has 2 divisors, whose sum is σ = 1606436043662. Its totient is φ = 1606436043660.

The previous prime is 1606436043659. The next prime is 1606436043697. The reversal of 1606436043661 is 1663406346061.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1548048570436 + 58387473225 = 1244206^2 + 241635^2 .

It is a cyclic number.

It is not a de Polignac number, because 1606436043661 - 2¹ = 1606436043659 is a prime.

Together with 1606436043659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1606436043601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 803218021830 + 803218021831.

It is an arithmetic number, because the mean of its divisors is an integer number (803218021831).

Almost surely, 2^{1606436043661} is an apocalyptic number.

It is an amenable number.

1606436043661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1606436043661 is an equidigital number, since it uses as much as digits as its factorization.

1606436043661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1119744, while the sum is 46.

The spelling of 1606436043661 in words is "one trillion, six hundred six billion, four hundred thirty-six million, forty-three thousand, six hundred sixty-one".