689685539 has 2 divisors, whose sum is σ = 689685540. Its totient is φ = 689685538.

The previous prime is 689685533. The next prime is 689685547. The reversal of 689685539 is 935586986.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 689685539 - 2⁴ = 689685523 is a prime.

It is a super-2 number, since 2×689685539² = 951332285411441042, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (689685533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344842769 + 344842770.

It is an arithmetic number, because the mean of its divisors is an integer number (344842770).

Almost surely, 2^689685539 is an apocalyptic number.

689685539 is a deficient number, since it is larger than the sum of its proper divisors (1).

689685539 is an equidigital number, since it uses as much as digits as its factorization.

689685539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13996800, while the sum is 59.

The square root of 689685539 is about 26261.8647281567. The cubic root of 689685539 is about 883.5213326051.

The spelling of 689685539 in words is "six hundred eighty-nine million, six hundred eighty-five thousand, five hundred thirty-nine".