3281215863781 has 2 divisors, whose sum is σ = 3281215863782. Its totient is φ = 3281215863780.

The previous prime is 3281215863721. The next prime is 3281215863907. The reversal of 3281215863781 is 1873685121823.

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., 1789532254756 + 1491683609025 = 1337734^2 + 1221345^2 .

It is a cyclic number.

It is not a de Polignac number, because 3281215863781 - 2¹⁵ = 3281215831013 is a prime.

It is a super-2 number, since 2×3281215863781² (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 (3281215863721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1640607931890 + 1640607931891.

It is an arithmetic number, because the mean of its divisors is an integer number (1640607931891).

Almost surely, 2^{3281215863781} is an apocalyptic number.

It is an amenable number.

3281215863781 is a deficient number, since it is larger than the sum of its proper divisors (1).

3281215863781 is an equidigital number, since it uses as much as digits as its factorization.

3281215863781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3870720, while the sum is 55.

The spelling of 3281215863781 in words is "three trillion, two hundred eighty-one billion, two hundred fifteen million, eight hundred sixty-three thousand, seven hundred eighty-one".