665461639553 has 2 divisors, whose sum is σ = 665461639554. Its totient is φ = 665461639552.

The previous prime is 665461639543. The next prime is 665461639607. The reversal of 665461639553 is 355936164566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 584044435984 + 81417203569 = 764228^2 + 285337^2 .

It is a cyclic number.

It is not a de Polignac number, because 665461639553 - 2⁴ = 665461639537 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665461639492 and 665461639501.

It is not a weakly prime, because it can be changed into another prime (665461639543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332730819776 + 332730819777.

It is an arithmetic number, because the mean of its divisors is an integer number (332730819777).

Almost surely, 2^665461639553 is an apocalyptic number.

It is an amenable number.

665461639553 is a deficient number, since it is larger than the sum of its proper divisors (1).

665461639553 is an equidigital number, since it uses as much as digits as its factorization.

665461639553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52488000, while the sum is 59.

The spelling of 665461639553 in words is "six hundred sixty-five billion, four hundred sixty-one million, six hundred thirty-nine thousand, five hundred fifty-three".