661083660529 has 2 divisors, whose sum is σ = 661083660530. Its totient is φ = 661083660528.

The previous prime is 661083660451. The next prime is 661083660541. The reversal of 661083660529 is 925066380166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 344277909504 + 316805751025 = 586752^2 + 562855^2 .

It is a cyclic number.

It is not a de Polignac number, because 661083660529 - 2²⁵ = 661050106097 is a prime.

It is a super-2 number, since 2×661083660529² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (661083660229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330541830264 + 330541830265.

It is an arithmetic number, because the mean of its divisors is an integer number (330541830265).

Almost surely, 2^661083660529 is an apocalyptic number.

It is an amenable number.

661083660529 is a deficient number, since it is larger than the sum of its proper divisors (1).

661083660529 is an equidigital number, since it uses as much as digits as its factorization.

661083660529 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2799360, while the sum is 52.

The spelling of 661083660529 in words is "six hundred sixty-one billion, eighty-three million, six hundred sixty thousand, five hundred twenty-nine".