689139623 has 2 divisors, whose sum is σ = 689139624. Its totient is φ = 689139622.

The previous prime is 689139617. The next prime is 689139643. The reversal of 689139623 is 326931986.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 689139623 - 2⁶ = 689139559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689139643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344569811 + 344569812.

It is an arithmetic number, because the mean of its divisors is an integer number (344569812).

Almost surely, 2^689139623 is an apocalyptic number.

689139623 is a deficient number, since it is larger than the sum of its proper divisors (1).

689139623 is an equidigital number, since it uses as much as digits as its factorization.

689139623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 47.

The square root of 689139623 is about 26251.4689684216. The cubic root of 689139623 is about 883.2881559269.

The spelling of 689139623 in words is "six hundred eighty-nine million, one hundred thirty-nine thousand, six hundred twenty-three".