688020138 has 48 divisors (see below), whose sum is σ = 1657184256. Its totient is φ = 204867360.

The previous prime is 688020131. The next prime is 688020163. The reversal of 688020138 is 831020886.

It is not an unprimeable number, because it can be changed into a prime (688020131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40170 + ... + 54677.

It is an arithmetic number, because the mean of its divisors is an integer number (34524672).

Almost surely, 2^688020138 is an apocalyptic number.

688020138 is an abundant number, since it is smaller than the sum of its proper divisors (969164118).

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

688020138 is a wasteful number, since it uses less digits than its factorization.

688020138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94899 (or 94896 counting only the distinct ones).

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

The square root of 688020138 is about 26230.1379714252. The cubic root of 688020138 is about 882.8096057021.

The spelling of 688020138 in words is "six hundred eighty-eight million, twenty thousand, one hundred thirty-eight".