65661677616656 has 80 divisors (see below), whose sum is σ = 140303016907200. Its totient is φ = 29521338892800.

The previous prime is 65661677616629. The next prime is 65661677616671.

65661677616656 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×65661677616656² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1591946 + ... + 11569686.

It is an arithmetic number, because the mean of its divisors is an integer number (1753787711340).

Almost surely, 2^{65661677616656} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65661677616656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70151508453600).

65661677616656 is an abundant number, since it is smaller than the sum of its proper divisors (74641339290544).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65661677616656 is a wasteful number, since it uses less digits than its factorization.

65661677616656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9978168 (or 9978162 counting only the distinct ones).

The product of its digits is 2057529600, while the sum is 74.

The spelling of 65661677616656 in words is "sixty-five trillion, six hundred sixty-one billion, six hundred seventy-seven million, six hundred sixteen thousand, six hundred fifty-six".