668756817161 has 8 divisors (see below), whose sum is σ = 703962571200. Its totient is φ = 633551865840.

The previous prime is 668756817139. The next prime is 668756817217. The reversal of 668756817161 is 161718657866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668756817161 is a prime.

It is a super-2 number, since 2×668756817161² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 668756817094 and 668756817103.

It is not an unprimeable number, because it can be changed into a prime (668756867161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2323820 + ... + 2595698.

It is an arithmetic number, because the mean of its divisors is an integer number (87995321400).

Almost surely, 2^668756817161 is an apocalyptic number.

It is an amenable number.

668756817161 is a deficient number, since it is larger than the sum of its proper divisors (35205754039).

668756817161 is a wasteful number, since it uses less digits than its factorization.

668756817161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401359.

The product of its digits is 20321280, while the sum is 62.

The spelling of 668756817161 in words is "six hundred sixty-eight billion, seven hundred fifty-six million, eight hundred seventeen thousand, one hundred sixty-one".