661044462511553 has 2 divisors, whose sum is σ = 661044462511554. Its totient is φ = 661044462511552.

The previous prime is 661044462511529. The next prime is 661044462511607. The reversal of 661044462511553 is 355115264440166.

661044462511553 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 604227134185024 + 56817328326529 = 24581032^2 + 7537727^2 .

It is a cyclic number.

It is not a de Polignac number, because 661044462511553 - 2¹⁰ = 661044462510529 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661044462511495 and 661044462511504.

It is not a weakly prime, because it can be changed into another prime (661044462511513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330522231255776 + 330522231255777.

It is an arithmetic number, because the mean of its divisors is an integer number (330522231255777).

Almost surely, 2^{661044462511553} is an apocalyptic number.

It is an amenable number.

661044462511553 is a deficient number, since it is larger than the sum of its proper divisors (1).

661044462511553 is an equidigital number, since it uses as much as digits as its factorization.

661044462511553 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368000, while the sum is 53.

The spelling of 661044462511553 in words is "six hundred sixty-one trillion, forty-four billion, four hundred sixty-two million, five hundred eleven thousand, five hundred fifty-three".