65661611616656 has 80 divisors (see below), whose sum is σ = 138934051484928. Its totient is φ = 29814090768000.

The previous prime is 65661611616641. The next prime is 65661611616673.

65661611616656 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×65661611616656² (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, 1965723251 + ... + 1965756653.

Almost surely, 2^{65661611616656} is an apocalyptic number.

It is an amenable number.

65661611616656 is an abundant number, since it is smaller than the sum of its proper divisors (73272439868272).

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

65661611616656 is a wasteful number, since it uses less digits than its factorization.

65661611616656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45100 (or 45094 counting only the distinct ones).

The product of its digits is 41990400, while the sum is 62.

The spelling of 65661611616656 in words is "sixty-five trillion, six hundred sixty-one billion, six hundred eleven million, six hundred sixteen thousand, six hundred fifty-six".