687632729 has 12 divisors (see below), whose sum is σ = 805745844. Its totient is φ = 585091584.

The previous prime is 687632723. The next prime is 687632747. The reversal of 687632729 is 927236786.

It can be written as a sum of positive squares in 2 ways, for example, as 452838400 + 234794329 = 21280^2 + 15323^2 .

It is not a de Polignac number, because 687632729 - 2¹² = 687628633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687632723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44504 + ... + 57929.

It is an arithmetic number, because the mean of its divisors is an integer number (67145487).

Almost surely, 2^687632729 is an apocalyptic number.

It is an amenable number.

687632729 is a deficient number, since it is larger than the sum of its proper divisors (118113115).

687632729 is a wasteful number, since it uses less digits than its factorization.

687632729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102584 (or 102577 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 50.

The square root of 687632729 is about 26222.7521248247. The cubic root of 687632729 is about 882.6438777046.

The spelling of 687632729 in words is "six hundred eighty-seven million, six hundred thirty-two thousand, seven hundred twenty-nine".