688547449 has 2 divisors, whose sum is σ = 688547450. Its totient is φ = 688547448.

The previous prime is 688547429. The next prime is 688547491. The reversal of 688547449 is 944745886.

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., 606735424 + 81812025 = 24632^2 + 9045^2 .

It is a cyclic number.

It is not a de Polignac number, because 688547449 - 2²⁹ = 151676537 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 688547449.

It is not a weakly prime, because it can be changed into another prime (688547429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344273724 + 344273725.

It is an arithmetic number, because the mean of its divisors is an integer number (344273725).

Almost surely, 2^688547449 is an apocalyptic number.

It is an amenable number.

688547449 is a deficient number, since it is larger than the sum of its proper divisors (1).

688547449 is an equidigital number, since it uses as much as digits as its factorization.

688547449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7741440, while the sum is 55.

The square root of 688547449 is about 26240.1876708228. The cubic root of 688547449 is about 883.0350818252.

The spelling of 688547449 in words is "six hundred eighty-eight million, five hundred forty-seven thousand, four hundred forty-nine".