661541053169 has 2 divisors, whose sum is σ = 661541053170. Its totient is φ = 661541053168.

The previous prime is 661541053051. The next prime is 661541053181. The reversal of 661541053169 is 961350145166.

661541053169 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 460854972769 + 200686080400 = 678863^2 + 447980^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661541053169 is a prime.

It is a super-2 number, since 2×661541053169² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (661541052169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330770526584 + 330770526585.

It is an arithmetic number, because the mean of its divisors is an integer number (330770526585).

Almost surely, 2^661541053169 is an apocalyptic number.

It is an amenable number.

661541053169 is a deficient number, since it is larger than the sum of its proper divisors (1).

661541053169 is an equidigital number, since it uses as much as digits as its factorization.

661541053169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 583200, while the sum is 47.

The spelling of 661541053169 in words is "six hundred sixty-one billion, five hundred forty-one million, fifty-three thousand, one hundred sixty-nine".