65668966817 has 16 divisors (see below), whose sum is σ = 71441137872. Its totient is φ = 60110346240.

The previous prime is 65668966801. The next prime is 65668966819. The reversal of 65668966817 is 71866986656.

It is a happy number.

65668966817 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 1591132321 + 64077834496 = 39889^2 + 253136^2 .

It is not a de Polignac number, because 65668966817 - 2⁴ = 65668966801 is a prime.

It is a super-2 number, since 2×65668966817² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65668966819) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1565003 + ... + 1606415.

It is an arithmetic number, because the mean of its divisors is an integer number (4465071117).

Almost surely, 2^65668966817 is an apocalyptic number.

It is an amenable number.

65668966817 is a deficient number, since it is larger than the sum of its proper divisors (5772171055).

65668966817 is a wasteful number, since it uses less digits than its factorization.

65668966817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43988.

The product of its digits is 156764160, while the sum is 68.

The spelling of 65668966817 in words is "sixty-five billion, six hundred sixty-eight million, nine hundred sixty-six thousand, eight hundred seventeen".