684742129 has 2 divisors, whose sum is σ = 684742130. Its totient is φ = 684742128.

The previous prime is 684742111. The next prime is 684742147. The reversal of 684742129 is 921247486.

It is a balanced prime because it is at equal distance from previous prime (684742111) and next prime (684742147).

It can be written as a sum of positive squares in only one way, i.e., 650250000 + 34492129 = 25500^2 + 5873^2 .

It is a cyclic number.

It is not a de Polignac number, because 684742129 - 2¹³ = 684733937 is a prime.

It is not a weakly prime, because it can be changed into another prime (684742829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342371064 + 342371065.

It is an arithmetic number, because the mean of its divisors is an integer number (342371065).

Almost surely, 2^684742129 is an apocalyptic number.

It is an amenable number.

684742129 is a deficient number, since it is larger than the sum of its proper divisors (1).

684742129 is an equidigital number, since it uses as much as digits as its factorization.

684742129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 43.

The square root of 684742129 is about 26167.5778206543. The cubic root of 684742129 is about 881.4053513222.

The spelling of 684742129 in words is "six hundred eighty-four million, seven hundred forty-two thousand, one hundred twenty-nine".