1665510660953 has 2 divisors, whose sum is σ = 1665510660954. Its totient is φ = 1665510660952.

The previous prime is 1665510660949. The next prime is 1665510661057. The reversal of 1665510660953 is 3590660155661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 928047075904 + 737463585049 = 963352^2 + 858757^2 .

It is an emirp because it is prime and its reverse (3590660155661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1665510660953 - 2² = 1665510660949 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1665510660895 and 1665510660904.

It is not a weakly prime, because it can be changed into another prime (1665510665953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832755330476 + 832755330477.

It is an arithmetic number, because the mean of its divisors is an integer number (832755330477).

Almost surely, 2^{1665510660953} is an apocalyptic number.

It is an amenable number.

1665510660953 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665510660953 is an equidigital number, since it uses as much as digits as its factorization.

1665510660953 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4374000, while the sum is 53.

The spelling of 1665510660953 in words is "one trillion, six hundred sixty-five billion, five hundred ten million, six hundred sixty thousand, nine hundred fifty-three".