68520406685 has 4 divisors (see below), whose sum is σ = 82224488028. Its totient is φ = 54816325344.

The previous prime is 68520406673. The next prime is 68520406687. The reversal of 68520406685 is 58660402586.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 29993390596 + 38527016089 = 173186^2 + 196283^2 .

It is a cyclic number.

It is not a de Polignac number, because 68520406685 - 2³² = 64225439389 is a prime.

It is a super-2 number, since 2×68520406685² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68520406687) 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, 6852040664 + ... + 6852040673.

It is an arithmetic number, because the mean of its divisors is an integer number (20556122007).

Almost surely, 2^68520406685 is an apocalyptic number.

It is an amenable number.

68520406685 is a deficient number, since it is larger than the sum of its proper divisors (13704081343).

68520406685 is a wasteful number, since it uses less digits than its factorization.

68520406685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13704081342.

The product of its (nonzero) digits is 2764800, while the sum is 50.

The spelling of 68520406685 in words is "sixty-eight billion, five hundred twenty million, four hundred six thousand, six hundred eighty-five".