68564861681 has 4 divisors (see below), whose sum is σ = 70159393392. Its totient is φ = 66970329972.

The previous prime is 68564861671. The next prime is 68564861753. The reversal of 68564861681 is 18616846586.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68564861681 is a prime.

It is a super-2 number, since 2×68564861681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 68564861681.

It is not an unprimeable number, because it can be changed into a prime (68564861611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 797265791 + ... + 797265876.

It is an arithmetic number, because the mean of its divisors is an integer number (17539848348).

Almost surely, 2^68564861681 is an apocalyptic number.

It is an amenable number.

68564861681 is a deficient number, since it is larger than the sum of its proper divisors (1594531711).

68564861681 is a wasteful number, since it uses less digits than its factorization.

68564861681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1594531710.

The product of its digits is 13271040, while the sum is 59.

The spelling of 68564861681 in words is "sixty-eight billion, five hundred sixty-four million, eight hundred sixty-one thousand, six hundred eighty-one".