687244729 has 2 divisors, whose sum is σ = 687244730. Its totient is φ = 687244728.

The previous prime is 687244717. The next prime is 687244759. The reversal of 687244729 is 927442786.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 418120704 + 269124025 = 20448^2 + 16405^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687244729 is a prime.

It is not a weakly prime, because it can be changed into another prime (687244759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343622364 + 343622365.

It is an arithmetic number, because the mean of its divisors is an integer number (343622365).

Almost surely, 2^687244729 is an apocalyptic number.

It is an amenable number.

687244729 is a deficient number, since it is larger than the sum of its proper divisors (1).

687244729 is an equidigital number, since it uses as much as digits as its factorization.

687244729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1354752, while the sum is 49.

The square root of 687244729 is about 26215.3529253375. The cubic root of 687244729 is about 882.4778344846.

The spelling of 687244729 in words is "six hundred eighty-seven million, two hundred forty-four thousand, seven hundred twenty-nine".