684897449 has 2 divisors, whose sum is σ = 684897450. Its totient is φ = 684897448.

The previous prime is 684897439. The next prime is 684897457. The reversal of 684897449 is 944798486.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 684764224 + 133225 = 26168^2 + 365^2 .

It is a cyclic number.

It is not a de Polignac number, because 684897449 - 2²⁰ = 683848873 is a prime.

It is not a weakly prime, because it can be changed into another prime (684897419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342448724 + 342448725.

It is an arithmetic number, because the mean of its divisors is an integer number (342448725).

Almost surely, 2^684897449 is an apocalyptic number.

It is an amenable number.

684897449 is a deficient number, since it is larger than the sum of its proper divisors (1).

684897449 is an equidigital number, since it uses as much as digits as its factorization.

684897449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13934592, while the sum is 59.

The square root of 684897449 is about 26170.5454471243. The cubic root of 684897449 is about 881.4719893181.

The spelling of 684897449 in words is "six hundred eighty-four million, eight hundred ninety-seven thousand, four hundred forty-nine".