688240220 has 24 divisors (see below), whose sum is σ = 1460208624. Its totient is φ = 272457216.

The previous prime is 688240213. The next prime is 688240237. The reversal of 688240220 is 22042886.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175442 + ... + 179321.

It is an arithmetic number, because the mean of its divisors is an integer number (60842026).

Almost surely, 2^688240220 is an apocalyptic number.

It is an amenable number.

688240220 is an abundant number, since it is smaller than the sum of its proper divisors (771968404).

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

688240220 is a wasteful number, since it uses less digits than its factorization.

688240220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354869 (or 354867 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 32.

The square root of 688240220 is about 26234.3328483878. The cubic root of 688240220 is about 882.9037259079.

The spelling of 688240220 in words is "six hundred eighty-eight million, two hundred forty thousand, two hundred twenty".