678581161 has 4 divisors (see below), whose sum is σ = 682903492. Its totient is φ = 674258832.

The previous prime is 678581153. The next prime is 678581173. The reversal of 678581161 is 161185876.

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 381225625 + 297355536 = 19525^2 + 17244^2 .

It is a cyclic number.

It is not a de Polignac number, because 678581161 - 2³ = 678581153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678521161) 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, 2160930 + ... + 2161243.

It is an arithmetic number, because the mean of its divisors is an integer number (170725873).

Almost surely, 2^678581161 is an apocalyptic number.

It is an amenable number.

678581161 is a deficient number, since it is larger than the sum of its proper divisors (4322331).

678581161 is a wasteful number, since it uses less digits than its factorization.

678581161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4322330.

The product of its digits is 80640, while the sum is 43.

The square root of 678581161 is about 26049.5904190450. The cubic root of 678581161 is about 878.7539013618.

The spelling of 678581161 in words is "six hundred seventy-eight million, five hundred eighty-one thousand, one hundred sixty-one".