661083660541 has 2 divisors, whose sum is σ = 661083660542. Its totient is φ = 661083660540.

The previous prime is 661083660529. The next prime is 661083660551. The reversal of 661083660541 is 145066380166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 362343802500 + 298739858041 = 601950^2 + 546571^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661083660541 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661083660491 and 661083660500.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661083660551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330541830270 + 330541830271.

It is an arithmetic number, because the mean of its divisors is an integer number (330541830271).

Almost surely, 2^661083660541 is an apocalyptic number.

It is an amenable number.

661083660541 is a deficient number, since it is larger than the sum of its proper divisors (1).

661083660541 is an equidigital number, since it uses as much as digits as its factorization.

661083660541 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 622080, while the sum is 46.

The spelling of 661083660541 in words is "six hundred sixty-one billion, eighty-three million, six hundred sixty thousand, five hundred forty-one".