689135231 has 2 divisors, whose sum is σ = 689135232. Its totient is φ = 689135230.

The previous prime is 689135191. The next prime is 689135233. The reversal of 689135231 is 132531986.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 689135231 - 2¹⁰ = 689134207 is a prime.

It is a super-2 number, since 2×689135231² = 949814733210846722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 689135233, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689135233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344567615 + 344567616.

It is an arithmetic number, because the mean of its divisors is an integer number (344567616).

Almost surely, 2^689135231 is an apocalyptic number.

689135231 is a deficient number, since it is larger than the sum of its proper divisors (1).

689135231 is an equidigital number, since it uses as much as digits as its factorization.

689135231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 38.

The square root of 689135231 is about 26251.3853158267. The cubic root of 689135231 is about 883.2862794761.

The spelling of 689135231 in words is "six hundred eighty-nine million, one hundred thirty-five thousand, two hundred thirty-one".