687022128 has 160 divisors (see below), whose sum is σ = 2154862080. Its totient is φ = 208293120.

The previous prime is 687022097. The next prime is 687022129. The reversal of 687022128 is 821220786.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 687022092 and 687022101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687022129) 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 31 ways as a sum of consecutive naturals, for example, 397875 + ... + 399597.

It is an arithmetic number, because the mean of its divisors is an integer number (13467888).

Almost surely, 2^687022128 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 687022128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1077431040).

687022128 is an abundant number, since it is smaller than the sum of its proper divisors (1467839952).

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

687022128 is a wasteful number, since it uses less digits than its factorization.

687022128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1824 (or 1812 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 687022128 is about 26211.1069586921. The cubic root of 687022128 is about 882.3825449644.

The spelling of 687022128 in words is "six hundred eighty-seven million, twenty-two thousand, one hundred twenty-eight".