688353581 has 2 divisors, whose sum is σ = 688353582. Its totient is φ = 688353580.

The previous prime is 688353571. The next prime is 688353643. The reversal of 688353581 is 185353886.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 500416900 + 187936681 = 22370^2 + 13709^2 .

It is a cyclic number.

It is not a de Polignac number, because 688353581 - 2²⁶ = 621244717 is a prime.

It is a super-2 number, since 2×688353581² = 947661304951047122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688353571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344176790 + 344176791.

It is an arithmetic number, because the mean of its divisors is an integer number (344176791).

Almost surely, 2^688353581 is an apocalyptic number.

It is an amenable number.

688353581 is a deficient number, since it is larger than the sum of its proper divisors (1).

688353581 is an equidigital number, since it uses as much as digits as its factorization.

688353581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 691200, while the sum is 47.

The square root of 688353581 is about 26236.4933060804. The cubic root of 688353581 is about 882.9521980119.

The spelling of 688353581 in words is "six hundred eighty-eight million, three hundred fifty-three thousand, five hundred eighty-one".