9864664147661 has 2 divisors, whose sum is σ = 9864664147662. Its totient is φ = 9864664147660.

The previous prime is 9864664147619. The next prime is 9864664147697. The reversal of 9864664147661 is 1667414664689.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8880191401225 + 984472746436 = 2979965^2 + 992206^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9864664147661 is a prime.

It is a super-2 number, since 2×9864664147661² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 9864664147591 and 9864664147600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9864664147561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4932332073830 + 4932332073831.

It is an arithmetic number, because the mean of its divisors is an integer number (4932332073831).

Almost surely, 2^{9864664147661} is an apocalyptic number.

It is an amenable number.

9864664147661 is a deficient number, since it is larger than the sum of its proper divisors (1).

9864664147661 is an equidigital number, since it uses as much as digits as its factorization.

9864664147661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 250822656, while the sum is 68.

The spelling of 9864664147661 in words is "nine trillion, eight hundred sixty-four billion, six hundred sixty-four million, one hundred forty-seven thousand, six hundred sixty-one".