1685542217741 has 2 divisors, whose sum is σ = 1685542217742. Its totient is φ = 1685542217740.

The previous prime is 1685542217717. The next prime is 1685542217873. The reversal of 1685542217741 is 1477122455861.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1048145964100 + 637396253641 = 1023790^2 + 798371^2 .

It is a cyclic number.

It is not a de Polignac number, because 1685542217741 - 2¹⁰ = 1685542216717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1685548217741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 842771108870 + 842771108871.

It is an arithmetic number, because the mean of its divisors is an integer number (842771108871).

Almost surely, 2^{1685542217741} is an apocalyptic number.

It is an amenable number.

1685542217741 is a deficient number, since it is larger than the sum of its proper divisors (1).

1685542217741 is an equidigital number, since it uses as much as digits as its factorization.

1685542217741 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3763200, while the sum is 53.

The spelling of 1685542217741 in words is "one trillion, six hundred eighty-five billion, five hundred forty-two million, two hundred seventeen thousand, seven hundred forty-one".