688066531 has 2 divisors, whose sum is σ = 688066532. Its totient is φ = 688066530.

The previous prime is 688066529. The next prime is 688066549. The reversal of 688066531 is 135660886.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 688066531 - 2¹ = 688066529 is a prime.

It is a super-2 number, since 2×688066531² = 946871102164747922, which contains 22 as substring.

Together with 688066529, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (688066501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344033265 + 344033266.

It is an arithmetic number, because the mean of its divisors is an integer number (344033266).

Almost surely, 2^688066531 is an apocalyptic number.

688066531 is a deficient number, since it is larger than the sum of its proper divisors (1).

688066531 is an equidigital number, since it uses as much as digits as its factorization.

688066531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 207360, while the sum is 43.

The square root of 688066531 is about 26231.0223018471. The cubic root of 688066531 is about 882.8294477887.

The spelling of 688066531 in words is "six hundred eighty-eight million, sixty-six thousand, five hundred thirty-one".