646321140005081 has 2 divisors, whose sum is σ = 646321140005082. Its totient is φ = 646321140005080.

The previous prime is 646321140005069. The next prime is 646321140005263. The reversal of 646321140005081 is 180500041123646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 581404940275600 + 64916199729481 = 24112340^2 + 8057059^2 .

It is a cyclic number.

It is not a de Polignac number, because 646321140005081 - 2¹⁴ = 646321139988697 is a prime.

It is a super-2 number, since 2×646321140005081² (a number of 30 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (646321140005381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323160570002540 + 323160570002541.

It is an arithmetic number, because the mean of its divisors is an integer number (323160570002541).

Almost surely, 2^{646321140005081} is an apocalyptic number.

It is an amenable number.

646321140005081 is a deficient number, since it is larger than the sum of its proper divisors (1).

646321140005081 is an equidigital number, since it uses as much as digits as its factorization.

646321140005081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 41.

The spelling of 646321140005081 in words is "six hundred forty-six trillion, three hundred twenty-one billion, one hundred forty million, five thousand, eighty-one".