1661676664663 has 2 divisors, whose sum is σ = 1661676664664. Its totient is φ = 1661676664662.

The previous prime is 1661676664633. The next prime is 1661676664693. The reversal of 1661676664663 is 3664666761661.

It is a balanced prime because it is at equal distance from previous prime (1661676664633) and next prime (1661676664693).

It is an emirp because it is prime and its reverse (3664666761661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661676664663 is a prime.

It is a super-2 number, since 2×1661676664663² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1661676664595 and 1661676664604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661676664633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830838332331 + 830838332332.

It is an arithmetic number, because the mean of its divisors is an integer number (830838332332).

Almost surely, 2^{1661676664663} is an apocalyptic number.

1661676664663 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661676664663 is an equidigital number, since it uses as much as digits as its factorization.

1661676664663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 141087744, while the sum is 64.

The spelling of 1661676664663 in words is "one trillion, six hundred sixty-one billion, six hundred seventy-six million, six hundred sixty-four thousand, six hundred sixty-three".