688541591 has 2 divisors, whose sum is σ = 688541592. Its totient is φ = 688541590.

The previous prime is 688541573. The next prime is 688541629. The reversal of 688541591 is 195145886.

It is a happy number.

688541591 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 not a de Polignac number, because 688541591 - 2¹⁴ = 688525207 is a prime.

It is a super-2 number, since 2×688541591² = 948179045073622562, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688541561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344270795 + 344270796.

It is an arithmetic number, because the mean of its divisors is an integer number (344270796).

Almost surely, 2^688541591 is an apocalyptic number.

688541591 is a deficient number, since it is larger than the sum of its proper divisors (1).

688541591 is an equidigital number, since it uses as much as digits as its factorization.

688541591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 345600, while the sum is 47.

The square root of 688541591 is about 26240.0760479081. The cubic root of 688541591 is about 883.0325775998.

The spelling of 688541591 in words is "six hundred eighty-eight million, five hundred forty-one thousand, five hundred ninety-one".