677781217 has 4 divisors (see below), whose sum is σ = 680418756. Its totient is φ = 675143680.

The previous prime is 677781199. The next prime is 677781229. The reversal of 677781217 is 712187776.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 651474576 + 26306641 = 25524^2 + 5129^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-677781217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (677781317) 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, 1318384 + ... + 1318897.

It is an arithmetic number, because the mean of its divisors is an integer number (170104689).

Almost surely, 2^677781217 is an apocalyptic number.

It is an amenable number.

677781217 is a deficient number, since it is larger than the sum of its proper divisors (2637539).

677781217 is a wasteful number, since it uses less digits than its factorization.

677781217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2637538.

The product of its digits is 230496, while the sum is 46.

The square root of 677781217 is about 26034.2316383641. The cubic root of 677781217 is about 878.4084598447.

The spelling of 677781217 in words is "six hundred seventy-seven million, seven hundred eighty-one thousand, two hundred seventeen".