661313802241 has 2 divisors, whose sum is σ = 661313802242. Its totient is φ = 661313802240.

The previous prime is 661313802217. The next prime is 661313802277. The reversal of 661313802241 is 142208313166.

661313802241 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 617128080625 + 44185721616 = 785575^2 + 210204^2 .

It is a cyclic number.

It is not a de Polignac number, because 661313802241 - 2⁵ = 661313802209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 661313802241.

It is not a weakly prime, because it can be changed into another prime (661313862241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330656901120 + 330656901121.

It is an arithmetic number, because the mean of its divisors is an integer number (330656901121).

Almost surely, 2^661313802241 is an apocalyptic number.

It is an amenable number.

661313802241 is a deficient number, since it is larger than the sum of its proper divisors (1).

661313802241 is an equidigital number, since it uses as much as digits as its factorization.

661313802241 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 37.

The spelling of 661313802241 in words is "six hundred sixty-one billion, three hundred thirteen million, eight hundred two thousand, two hundred forty-one".