677487781 has 2 divisors, whose sum is σ = 677487782. Its totient is φ = 677487780.

The previous prime is 677487779. The next prime is 677487799. The reversal of 677487781 is 187784776.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 662238756 + 15249025 = 25734^2 + 3905^2 .

It is a cyclic number.

It is not a de Polignac number, because 677487781 - 2¹ = 677487779 is a prime.

It is a super-2 number, since 2×677487781² = 917979386808607922, which contains 22 as substring.

Together with 677487779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (677487581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 338743890 + 338743891.

It is an arithmetic number, because the mean of its divisors is an integer number (338743891).

Almost surely, 2^677487781 is an apocalyptic number.

It is an amenable number.

677487781 is a deficient number, since it is larger than the sum of its proper divisors (1).

677487781 is an equidigital number, since it uses as much as digits as its factorization.

677487781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3687936, while the sum is 55.

The square root of 677487781 is about 26028.5954480836. The cubic root of 677487781 is about 878.2816766170.

The spelling of 677487781 in words is "six hundred seventy-seven million, four hundred eighty-seven thousand, seven hundred eighty-one".