688534531 has 2 divisors, whose sum is σ = 688534532. Its totient is φ = 688534530.

The previous prime is 688534523. The next prime is 688534541. The reversal of 688534531 is 135435886.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 688534531 - 2³ = 688534523 is a prime.

It is a super-2 number, since 2×688534531² = 948159600758779922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (688534541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344267265 + 344267266.

It is an arithmetic number, because the mean of its divisors is an integer number (344267266).

Almost surely, 2^688534531 is an apocalyptic number.

688534531 is a deficient number, since it is larger than the sum of its proper divisors (1).

688534531 is an equidigital number, since it uses as much as digits as its factorization.

688534531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 345600, while the sum is 43.

The square root of 688534531 is about 26239.9415205141. The cubic root of 688534531 is about 883.0295595147.

It can be divided in two parts, 6885345 and 31, that added together give a square (6885376 = 2624²).

The spelling of 688534531 in words is "six hundred eighty-eight million, five hundred thirty-four thousand, five hundred thirty-one".