1688968816 has 20 divisors (see below), whose sum is σ = 3385218600. Its totient is φ = 815364032.

The previous prime is 1688968781. The next prime is 1688968817. The reversal of 1688968816 is 6188698861.

It is a super-2 number, since 2×1688968816² = 5705231322840883712, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688968817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1819546 + ... + 1820473.

It is an arithmetic number, because the mean of its divisors is an integer number (169260930).

Almost surely, 2^1688968816 is an apocalyptic number.

1688968816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1688968816 is an abundant number, since it is smaller than the sum of its proper divisors (1696249784).

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

1688968816 is a wasteful number, since it uses less digits than its factorization.

1688968816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3640056 (or 3640050 counting only the distinct ones).

The product of its digits is 7962624, while the sum is 61.

The square root of 1688968816 is about 41097.0657833379. The cubic root of 1688968816 is about 1190.8961110366.

The spelling of 1688968816 in words is "one billion, six hundred eighty-eight million, nine hundred sixty-eight thousand, eight hundred sixteen".