1664556554661 has 288 divisors, whose sum is σ = 3280881623040. Its totient is φ = 731674944000.

The previous prime is 1664556554659. The next prime is 1664556554677.

1664556554661 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1664556554661 - 2¹ = 1664556554659 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1664556554595 and 1664556554604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664556554611) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 252930391 + ... + 252936971.

It is an arithmetic number, because the mean of its divisors is an integer number (11391950080).

Almost surely, 2^{1664556554661} is an apocalyptic number.

1664556554661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1664556554661 is a deficient number, since it is larger than the sum of its proper divisors (1616325068379).

1664556554661 is a wasteful number, since it uses less digits than its factorization.

1664556554661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6689 (or 6665 counting only the distinct ones).

The product of its digits is 77760000, while the sum is 60.

The spelling of 1664556554661 in words is "one trillion, six hundred sixty-four billion, five hundred fifty-six million, five hundred fifty-four thousand, six hundred sixty-one".