663873085481 has 2 divisors, whose sum is σ = 663873085482. Its totient is φ = 663873085480.

The previous prime is 663873085397. The next prime is 663873085493. The reversal of 663873085481 is 184580378366.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 597244569856 + 66628515625 = 772816^2 + 258125^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-663873085481 is a prime.

It is a super-2 number, since 2×663873085481² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 663873085481.

It is not a weakly prime, because it can be changed into another prime (663873085181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331936542740 + 331936542741.

It is an arithmetic number, because the mean of its divisors is an integer number (331936542741).

Almost surely, 2^663873085481 is an apocalyptic number.

It is an amenable number.

663873085481 is a deficient number, since it is larger than the sum of its proper divisors (1).

663873085481 is an equidigital number, since it uses as much as digits as its factorization.

663873085481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23224320, while the sum is 59.

The spelling of 663873085481 in words is "six hundred sixty-three billion, eight hundred seventy-three million, eighty-five thousand, four hundred eighty-one".