1765766566661 has 2 divisors, whose sum is σ = 1765766566662. Its totient is φ = 1765766566660.

The previous prime is 1765766566643. The next prime is 1765766566667. The reversal of 1765766566661 is 1666656675671.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1733080096225 + 32686470436 = 1316465^2 + 180794^2 .

It is a cyclic number.

It is not a de Polignac number, because 1765766566661 - 2¹⁸ = 1765766304517 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1765766566591 and 1765766566600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1765766566667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 882883283330 + 882883283331.

It is an arithmetic number, because the mean of its divisors is an integer number (882883283331).

Almost surely, 2^{1765766566661} is an apocalyptic number.

It is an amenable number.

1765766566661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1765766566661 is an equidigital number, since it uses as much as digits as its factorization.

1765766566661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 342921600, while the sum is 68.

The spelling of 1765766566661 in words is "one trillion, seven hundred sixty-five billion, seven hundred sixty-six million, five hundred sixty-six thousand, six hundred sixty-one".