687717461 has 2 divisors, whose sum is σ = 687717462. Its totient is φ = 687717460.

The previous prime is 687717377. The next prime is 687717467. The reversal of 687717461 is 164717786.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 539632900 + 148084561 = 23230^2 + 12169^2 .

It is a cyclic number.

It is not a de Polignac number, because 687717461 - 2¹⁸ = 687455317 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687717467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343858730 + 343858731.

It is an arithmetic number, because the mean of its divisors is an integer number (343858731).

Almost surely, 2^687717461 is an apocalyptic number.

It is an amenable number.

687717461 is a deficient number, since it is larger than the sum of its proper divisors (1).

687717461 is an equidigital number, since it uses as much as digits as its factorization.

687717461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 395136, while the sum is 47.

The square root of 687717461 is about 26224.3676949512. The cubic root of 687717461 is about 882.6801301526.

The spelling of 687717461 in words is "six hundred eighty-seven million, seven hundred seventeen thousand, four hundred sixty-one".