678161 has 4 divisors (see below), whose sum is σ = 739824. Its totient is φ = 616500.

The previous prime is 678157. The next prime is 678169. The reversal of 678161 is 161876.

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 not a de Polignac number, because 678161 - 2² = 678157 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678169) 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, 30815 + ... + 30836.

It is an arithmetic number, because the mean of its divisors is an integer number (184956).

2⁶⁷⁸¹⁶¹ is an apocalyptic number.

It is an amenable number.

678161 is a deficient number, since it is larger than the sum of its proper divisors (61663).

678161 is a wasteful number, since it uses less digits than its factorization.

678161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61662.

The product of its digits is 2016, while the sum is 29.

The square root of 678161 is about 823.5053126726. The cubic root of 678161 is about 87.8572496214.

It can be divided in two parts, 67 and 8161, that added together give a palindrome (8228).

The spelling of 678161 in words is "six hundred seventy-eight thousand, one hundred sixty-one".