679780 has 24 divisors (see below), whose sum is σ = 1464120. Its totient is φ = 264960.

The previous prime is 679753. The next prime is 679781. The reversal of 679780 is 87976.

679780 = T₁₆₄ + T₁₆₅ + ... + T₂₀₃.

It can be written as a sum of positive squares in 4 ways, for example, as 4096 + 675684 = 64^2 + 822^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (679781) by changing a digit.

679780 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 406 + ... + 1234.

It is an arithmetic number, because the mean of its divisors is an integer number (61005).

2⁶⁷⁹⁷⁸⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 679780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (732060).

679780 is an abundant number, since it is smaller than the sum of its proper divisors (784340).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

679780 is a wasteful number, since it uses less digits than its factorization.

679780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 879 (or 877 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 679780 is about 824.4877197387. The cubic root of 679780 is about 87.9271090621.

The spelling of 679780 in words is "six hundred seventy-nine thousand, seven hundred eighty".