678328561 has 4 divisors (see below), whose sum is σ = 680378224. Its totient is φ = 676278900.

The previous prime is 678328529. The next prime is 678328571. The reversal of 678328561 is 165823876.

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 678328561 - 2⁵ = 678328529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678328571) 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, 1024335 + ... + 1024996.

It is an arithmetic number, because the mean of its divisors is an integer number (170094556).

Almost surely, 2^678328561 is an apocalyptic number.

It is an amenable number.

678328561 is a deficient number, since it is larger than the sum of its proper divisors (2049663).

678328561 is a wasteful number, since it uses less digits than its factorization.

678328561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2049662.

The product of its digits is 483840, while the sum is 46.

The square root of 678328561 is about 26044.7415230023. The cubic root of 678328561 is about 878.6448499091.

It can be divided in two parts, 6783 and 28561, that added together give a square (35344 = 188²).

The spelling of 678328561 in words is "six hundred seventy-eight million, three hundred twenty-eight thousand, five hundred sixty-one".