9665666665784 has 8 divisors (see below), whose sum is σ = 18123124998360. Its totient is φ = 4832833332888.

The previous prime is 9665666665769. The next prime is 9665666665799. The reversal of 9665666665784 is 4875666665669.

It is an interprime number because it is at equal distance from previous prime (9665666665769) and next prime (9665666665799).

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×9665666665784² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 9665666665699 and 9665666665708.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 604104166604 + ... + 604104166619.

It is an arithmetic number, because the mean of its divisors is an integer number (2265390624795).

Almost surely, 2^{9665666665784} is an apocalyptic number.

It is an amenable number.

9665666665784 is a deficient number, since it is larger than the sum of its proper divisors (8457458332576).

9665666665784 is a wasteful number, since it uses less digits than its factorization.

9665666665784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208208333229 (or 1208208333225 counting only the distinct ones).

The product of its digits is 14108774400, while the sum is 80.

The spelling of 9665666665784 in words is "nine trillion, six hundred sixty-five billion, six hundred sixty-six million, six hundred sixty-five thousand, seven hundred eighty-four".