689406191 has 2 divisors, whose sum is σ = 689406192. Its totient is φ = 689406190.

The previous prime is 689406169. The next prime is 689406239. The reversal of 689406191 is 191604986.

689406191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689406191 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689406101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344703095 + 344703096.

It is an arithmetic number, because the mean of its divisors is an integer number (344703096).

Almost surely, 2^689406191 is an apocalyptic number.

689406191 is a deficient number, since it is larger than the sum of its proper divisors (1).

689406191 is an equidigital number, since it uses as much as digits as its factorization.

689406191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 689406191 is about 26256.5456791254. The cubic root of 689406191 is about 883.4020302888.

The spelling of 689406191 in words is "six hundred eighty-nine million, four hundred six thousand, one hundred ninety-one".