689420969 has 2 divisors, whose sum is σ = 689420970. Its totient is φ = 689420968.

The previous prime is 689420939. The next prime is 689420971. The reversal of 689420969 is 969024986.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 688800025 + 620944 = 26245^2 + 788^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689420969 is a prime.

It is a super-2 number, since 2×689420969² = 950602544993797922, which contains 22 as substring.

Together with 689420971, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 689420969.

It is not a weakly prime, because it can be changed into another prime (689420939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344710484 + 344710485.

It is an arithmetic number, because the mean of its divisors is an integer number (344710485).

Almost surely, 2^689420969 is an apocalyptic number.

It is an amenable number.

689420969 is a deficient number, since it is larger than the sum of its proper divisors (1).

689420969 is an equidigital number, since it uses as much as digits as its factorization.

689420969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1679616, while the sum is 53.

The square root of 689420969 is about 26256.8270931581. The cubic root of 689420969 is about 883.4083423982.

The spelling of 689420969 in words is "six hundred eighty-nine million, four hundred twenty thousand, nine hundred sixty-nine".