1688726416 has 90 divisors (see below), whose sum is σ = 3765362982. Its totient is φ = 733224960.

The previous prime is 1688726407. The next prime is 1688726437. The reversal of 1688726416 is 6146278861.

It can be written as a sum of positive squares in 9 ways, for example, as 285474816 + 1403251600 = 16896^2 + 37460^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1688726416.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 780376 + ... + 782536.

Almost surely, 2^1688726416 is an apocalyptic number.

1688726416 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1688726416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1882681491).

1688726416 is an abundant number, since it is smaller than the sum of its proper divisors (2076636566).

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

1688726416 is a wasteful number, since it uses less digits than its factorization.

1688726416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2229 (or 2193 counting only the distinct ones).

The product of its digits is 774144, while the sum is 49.

The square root of 1688726416 is about 41094.1165618632. The cubic root of 1688726416 is about 1190.8391360300.

The spelling of 1688726416 in words is "one billion, six hundred eighty-eight million, seven hundred twenty-six thousand, four hundred sixteen".