677946209 has 2 divisors, whose sum is σ = 677946210. Its totient is φ = 677946208.

The previous prime is 677946187. The next prime is 677946251. The reversal of 677946209 is 902649776.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 433805584 + 244140625 = 20828^2 + 15625^2 .

It is a cyclic number.

It is not a de Polignac number, because 677946209 - 2²⁰ = 676897633 is a prime.

It is a super-2 number, since 2×677946209² = 919222124594943362, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (677946259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 338973104 + 338973105.

It is an arithmetic number, because the mean of its divisors is an integer number (338973105).

Almost surely, 2^677946209 is an apocalyptic number.

It is an amenable number.

677946209 is a deficient number, since it is larger than the sum of its proper divisors (1).

677946209 is an equidigital number, since it uses as much as digits as its factorization.

677946209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1143072, while the sum is 50.

The square root of 677946209 is about 26037.4001966402. The cubic root of 677946209 is about 878.4797309306.

The spelling of 677946209 in words is "six hundred seventy-seven million, nine hundred forty-six thousand, two hundred nine".