3985398749669 has 2 divisors, whose sum is σ = 3985398749670. Its totient is φ = 3985398749668.

The previous prime is 3985398749641. The next prime is 3985398749723. The reversal of 3985398749669 is 9669478935893.

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., 3985361417569 + 37332100 = 1996337^2 + 6110^2 .

It is a cyclic number.

It is not a de Polignac number, because 3985398749669 - 2¹⁶ = 3985398684133 is a prime.

It is a super-3 number, since 3×3985398749669³ (a number of 39 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3985398749869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1992699374834 + 1992699374835.

It is an arithmetic number, because the mean of its divisors is an integer number (1992699374835).

Almost surely, 2^{3985398749669} is an apocalyptic number.

It is an amenable number.

3985398749669 is a deficient number, since it is larger than the sum of its proper divisors (1).

3985398749669 is an equidigital number, since it uses as much as digits as its factorization.

3985398749669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19046845440, while the sum is 86.

The spelling of 3985398749669 in words is "three trillion, nine hundred eighty-five billion, three hundred ninety-eight million, seven hundred forty-nine thousand, six hundred sixty-nine".