6688687531 has 2 divisors, whose sum is σ = 6688687532. Its totient is φ = 6688687530.

The previous prime is 6688687493. The next prime is 6688687589. The reversal of 6688687531 is 1357868866.

It is an a-pointer prime, because the next prime (6688687589) can be obtained adding 6688687531 to its sum of digits (58).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6688687531 - 2¹⁹ = 6688163243 is a prime.

It is a super-2 number, since 2×6688687531² = 89477081774709751922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6688687231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3344343765 + 3344343766.

It is an arithmetic number, because the mean of its divisors is an integer number (3344343766).

Almost surely, 2^6688687531 is an apocalyptic number.

6688687531 is a deficient number, since it is larger than the sum of its proper divisors (1).

6688687531 is an equidigital number, since it uses as much as digits as its factorization.

6688687531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11612160, while the sum is 58.

The square root of 6688687531 is about 81784.3966230723. The cubic root of 6688687531 is about 1884.1420229836.

The spelling of 6688687531 in words is "six billion, six hundred eighty-eight million, six hundred eighty-seven thousand, five hundred thirty-one".