688939144 has 16 divisors (see below), whose sum is σ = 1367747100. Its totient is φ = 324206592.

The previous prime is 688939123. The next prime is 688939151. The reversal of 688939144 is 441939886.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 683822500 + 5116644 = 26150^2 + 2262^2 .

It is a junction number, because it is equal to n+sod(n) for n = 688939091 and 688939100.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2532729 + ... + 2533000.

Almost surely, 2^688939144 is an apocalyptic number.

It is an amenable number.

688939144 is a deficient number, since it is larger than the sum of its proper divisors (678807956).

688939144 is a wasteful number, since it uses less digits than its factorization.

688939144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5065752 (or 5065748 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 52.

The square root of 688939144 is about 26247.6502567373. The cubic root of 688939144 is about 883.2024945724.

The spelling of 688939144 in words is "six hundred eighty-eight million, nine hundred thirty-nine thousand, one hundred forty-four".