687631829 has 2 divisors, whose sum is σ = 687631830. Its totient is φ = 687631828.

The previous prime is 687631817. The next prime is 687631859. The reversal of 687631829 is 928136786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 388168804 + 299463025 = 19702^2 + 17305^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687631829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687631859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343815914 + 343815915.

It is an arithmetic number, because the mean of its divisors is an integer number (343815915).

Almost surely, 2^687631829 is an apocalyptic number.

It is an amenable number.

687631829 is a deficient number, since it is larger than the sum of its proper divisors (1).

687631829 is an equidigital number, since it uses as much as digits as its factorization.

687631829 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 50.

The square root of 687631829 is about 26222.7349641490. The cubic root of 687631829 is about 882.6434926251.

The spelling of 687631829 in words is "six hundred eighty-seven million, six hundred thirty-one thousand, eight hundred twenty-nine".