684857429 has 2 divisors, whose sum is σ = 684857430. Its totient is φ = 684857428.

The previous prime is 684857423. The next prime is 684857471. The reversal of 684857429 is 924758486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 557054404 + 127803025 = 23602^2 + 11305^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-684857429 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684857423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342428714 + 342428715.

It is an arithmetic number, because the mean of its divisors is an integer number (342428715).

Almost surely, 2^684857429 is an apocalyptic number.

It is an amenable number.

684857429 is a deficient number, since it is larger than the sum of its proper divisors (1).

684857429 is an equidigital number, since it uses as much as digits as its factorization.

684857429 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3870720, while the sum is 53.

The square root of 684857429 is about 26169.7808359184. The cubic root of 684857429 is about 881.4548202289.

The spelling of 684857429 in words is "six hundred eighty-four million, eight hundred fifty-seven thousand, four hundred twenty-nine".