68780161 has 4 divisors (see below), whose sum is σ = 68808532. Its totient is φ = 68751792.

The previous prime is 68780111. The next prime is 68780183. The reversal of 68780161 is 16108786.

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 27499536 + 41280625 = 5244^2 + 6425^2 .

It is a cyclic number.

It is not a de Polignac number, because 68780161 - 2²³ = 60391553 is a prime.

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 68780161.

It is not an unprimeable number, because it can be changed into a prime (68780111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10170 + ... + 15523.

It is an arithmetic number, because the mean of its divisors is an integer number (17202133).

Almost surely, 2^68780161 is an apocalyptic number.

It is an amenable number.

68780161 is a deficient number, since it is larger than the sum of its proper divisors (28371).

68780161 is a wasteful number, since it uses less digits than its factorization.

68780161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28370.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 68780161 is about 8293.3805531882. The cubic root of 68780161 is about 409.7205333271.

The spelling of 68780161 in words is "sixty-eight million, seven hundred eighty thousand, one hundred sixty-one".