1660465543661 has 2 divisors, whose sum is σ = 1660465543662. Its totient is φ = 1660465543660.

The previous prime is 1660465543651. The next prime is 1660465543691. The reversal of 1660465543661 is 1663455640661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1579571376100 + 80894167561 = 1256810^2 + 284419^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1660465543661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1660465543621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830232771830 + 830232771831.

It is an arithmetic number, because the mean of its divisors is an integer number (830232771831).

Almost surely, 2^{1660465543661} is an apocalyptic number.

It is an amenable number.

1660465543661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1660465543661 is an equidigital number, since it uses as much as digits as its factorization.

1660465543661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9331200, while the sum is 53.

The spelling of 1660465543661 in words is "one trillion, six hundred sixty billion, four hundred sixty-five million, five hundred forty-three thousand, six hundred sixty-one".