688005220 has 48 divisors (see below), whose sum is σ = 1658563200. Its totient is φ = 234837504.

The previous prime is 688005211. The next prime is 688005229. The reversal of 688005220 is 22500886.

It is an interprime number because it is at equal distance from previous prime (688005211) and next prime (688005229).

It is not an unprimeable number, because it can be changed into a prime (688005229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20956 + ... + 42604.

It is an arithmetic number, because the mean of its divisors is an integer number (34553400).

Almost surely, 2^688005220 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688005220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (829281600).

688005220 is an abundant number, since it is smaller than the sum of its proper divisors (970557980).

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

688005220 is a wasteful number, since it uses less digits than its factorization.

688005220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21892 (or 21890 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 688005220 is about 26229.8536023364. The cubic root of 688005220 is about 882.8032251481.

Adding to 688005220 its product of nonzero digits (7680), we get a square (688012900 = 26230²).

The spelling of 688005220 in words is "six hundred eighty-eight million, five thousand, two hundred twenty".