688393331 has 2 divisors, whose sum is σ = 688393332. Its totient is φ = 688393330.

The previous prime is 688393319. The next prime is 688393333. The reversal of 688393331 is 133393886.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 688393331 - 2¹⁰ = 688392307 is a prime.

It is a super-2 number, since 2×688393331² = 947770756330551122, which contains 22 as substring.

Together with 688393333, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (688393333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344196665 + 344196666.

It is an arithmetic number, because the mean of its divisors is an integer number (344196666).

Almost surely, 2^688393331 is an apocalyptic number.

688393331 is a deficient number, since it is larger than the sum of its proper divisors (1).

688393331 is an equidigital number, since it uses as much as digits as its factorization.

688393331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 44.

The square root of 688393331 is about 26237.2508277830. The cubic root of 688393331 is about 882.9691934801.

The spelling of 688393331 in words is "six hundred eighty-eight million, three hundred ninety-three thousand, three hundred thirty-one".