3989210860781 has 2 divisors, whose sum is σ = 3989210860782. Its totient is φ = 3989210860780.

The previous prime is 3989210860769. The next prime is 3989210860807. The reversal of 3989210860781 is 1870680129893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2390146920100 + 1599063940681 = 1546010^2 + 1264541^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3989210860781 is a prime.

It is a super-2 number, since 2×3989210860781² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3989210860981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1994605430390 + 1994605430391.

It is an arithmetic number, because the mean of its divisors is an integer number (1994605430391).

Almost surely, 2^{3989210860781} is an apocalyptic number.

It is an amenable number.

3989210860781 is a deficient number, since it is larger than the sum of its proper divisors (1).

3989210860781 is an equidigital number, since it uses as much as digits as its factorization.

3989210860781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10450944, while the sum is 62.

The spelling of 3989210860781 in words is "three trillion, nine hundred eighty-nine billion, two hundred ten million, eight hundred sixty thousand, seven hundred eighty-one".