688636609231 has 2 divisors, whose sum is σ = 688636609232. Its totient is φ = 688636609230.

The previous prime is 688636609223. The next prime is 688636609261. The reversal of 688636609231 is 132906636886.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 688636609231 - 2³ = 688636609223 is a prime.

It is a super-2 number, since 2×688636609231² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688636609261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344318304615 + 344318304616.

It is an arithmetic number, because the mean of its divisors is an integer number (344318304616).

Almost surely, 2^688636609231 is an apocalyptic number.

688636609231 is a deficient number, since it is larger than the sum of its proper divisors (1).

688636609231 is an equidigital number, since it uses as much as digits as its factorization.

688636609231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13436928, while the sum is 58.

The spelling of 688636609231 in words is "six hundred eighty-eight billion, six hundred thirty-six million, six hundred nine thousand, two hundred thirty-one".