678860669 has 2 divisors, whose sum is σ = 678860670. Its totient is φ = 678860668.

The previous prime is 678860659. The next prime is 678860713. The reversal of 678860669 is 966068876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 500103769 + 178756900 = 22363^2 + 13370^2 .

It is a cyclic number.

It is not a de Polignac number, because 678860669 - 2²⁴ = 662083453 is a prime.

It is a super-2 number, since 2×678860669² = 921703615830255122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678860659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339430334 + 339430335.

It is an arithmetic number, because the mean of its divisors is an integer number (339430335).

Almost surely, 2^678860669 is an apocalyptic number.

It is an amenable number.

678860669 is a deficient number, since it is larger than the sum of its proper divisors (1).

678860669 is an equidigital number, since it uses as much as digits as its factorization.

678860669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5225472, while the sum is 56.

The square root of 678860669 is about 26054.9547879093. The cubic root of 678860669 is about 878.8745378917.

The spelling of 678860669 in words is "six hundred seventy-eight million, eight hundred sixty thousand, six hundred sixty-nine".