688294129 has 2 divisors, whose sum is σ = 688294130. Its totient is φ = 688294128.

The previous prime is 688294127. The next prime is 688294157. The reversal of 688294129 is 921492886.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 426339904 + 261954225 = 20648^2 + 16185^2 .

It is a cyclic number.

It is not a de Polignac number, because 688294129 - 2¹ = 688294127 is a prime.

Together with 688294127, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (688294127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344147064 + 344147065.

It is an arithmetic number, because the mean of its divisors is an integer number (344147065).

Almost surely, 2^688294129 is an apocalyptic number.

It is an amenable number.

688294129 is a deficient number, since it is larger than the sum of its proper divisors (1).

688294129 is an equidigital number, since it uses as much as digits as its factorization.

688294129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 497664, while the sum is 49.

The square root of 688294129 is about 26235.3602795921. The cubic root of 688294129 is about 882.9267775561.

The spelling of 688294129 in words is "six hundred eighty-eight million, two hundred ninety-four thousand, one hundred twenty-nine".