1665510661057 has 2 divisors, whose sum is σ = 1665510661058. Its totient is φ = 1665510661056.

The previous prime is 1665510660953. The next prime is 1665510661117. The reversal of 1665510661057 is 7501660155661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 963226436481 + 702284224576 = 981441^2 + 838024^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665510661057 - 2²³ = 1665502272449 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1665510661057.

It is not a weakly prime, because it can be changed into another prime (1665510661657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832755330528 + 832755330529.

It is an arithmetic number, because the mean of its divisors is an integer number (832755330529).

Almost surely, 2^{1665510661057} is an apocalyptic number.

It is an amenable number.

1665510661057 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665510661057 is an equidigital number, since it uses as much as digits as its factorization.

1665510661057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1134000, while the sum is 49.

The spelling of 1665510661057 in words is "one trillion, six hundred sixty-five billion, five hundred ten million, six hundred sixty-one thousand, fifty-seven".