1688864 has 24 divisors (see below), whose sum is σ = 3367980. Its totient is φ = 833536.

The previous prime is 1688861. The next prime is 1688887. The reversal of 1688864 is 4688861.

It can be written as a sum of positive squares in 2 ways, for example, as 1669264 + 19600 = 1292^2 + 140^2 .

It is a super-2 number, since 2×1688864² = 5704523220992, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1688861) 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, 2552 + ... + 3144.

2^1688864 is an apocalyptic number.

It is an amenable number.

1688864 is a deficient number, since it is larger than the sum of its proper divisors (1679116).

1688864 is an equidigital number, since it uses as much as digits as its factorization.

1688864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692 (or 684 counting only the distinct ones).

The product of its digits is 73728, while the sum is 41.

The square root of 1688864 is about 1299.5630034746. The cubic root of 1688864 is about 119.0871475186.

It can be divided in two parts, 1688 and 864, that added together give a palindrome (2552).

The spelling of 1688864 in words is "one million, six hundred eighty-eight thousand, eight hundred sixty-four".