689420939 has 2 divisors, whose sum is σ = 689420940. Its totient is φ = 689420938.

The previous prime is 689420917. The next prime is 689420969. The reversal of 689420939 is 939024986.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689420939 is a prime.

It is a super-2 number, since 2×689420939² = 950602462263283442, 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 (689420969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344710469 + 344710470.

It is an arithmetic number, because the mean of its divisors is an integer number (344710470).

Almost surely, 2^689420939 is an apocalyptic number.

689420939 is a deficient number, since it is larger than the sum of its proper divisors (1).

689420939 is an equidigital number, since it uses as much as digits as its factorization.

689420939 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 839808, while the sum is 50.

The square root of 689420939 is about 26256.8265218781. The cubic root of 689420939 is about 883.4083295844.

The spelling of 689420939 in words is "six hundred eighty-nine million, four hundred twenty thousand, nine hundred thirty-nine".