688130802 has 54 divisors (see below), whose sum is σ = 1555005933. Its totient is φ = 228375288.

The previous prime is 688130801. The next prime is 688130827. The reversal of 688130802 is 208031886.

It can be written as a sum of positive squares in 2 ways, for example, as 518063121 + 170067681 = 22761^2 + 13041^2 .

It is a tau number, because it is divible by the number of its divisors (54).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=18549.

It is a super-2 number, since 2×688130802² = 947048001322326408, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (688130801) 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 in 26 ways as a sum of consecutive naturals, for example, 3004824 + ... + 3005052.

Almost surely, 2^688130802 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688130802

688130802 is an abundant number, since it is smaller than the sum of its proper divisors (866875131).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

688130802 is an frugal number, since it uses more digits than its factorization.

688130802 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 688130802 is about 26232.2473684585. The cubic root of 688130802 is about 882.8569347454.

Multiplying 688130802 by its product of nonzero digits (18432), we get a square (12683626942464 = 3561408²).

The spelling of 688130802 in words is "six hundred eighty-eight million, one hundred thirty thousand, eight hundred two".