1688436 has 18 divisors (see below), whose sum is σ = 4268082. Its totient is φ = 562800.

The previous prime is 1688413. The next prime is 1688443. The reversal of 1688436 is 6348861.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1664100 + 24336 = 1290^2 + 156^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×1688436² = 5701632252192, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 46901 = 1688436 / (1 + 6 + 8 + 8 + 4 + 3 + 6).

It is a d-powerful number, because it can be written as 1 + 6⁵ + 8 + 8 + 4⁵ + 3 + 6⁸ .

It is a self number, because there is not a number n which added to its sum of digits gives 1688436.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 23415 + ... + 23486.

2^1688436 is an apocalyptic number.

It is an amenable number.

1688436 is an abundant number, since it is smaller than the sum of its proper divisors (2579646).

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

1688436 is a wasteful number, since it uses less digits than its factorization.

1688436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46911 (or 46906 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 1688436 is about 1299.3983223015. The cubic root of 1688436 is about 119.0770867904.

The spelling of 1688436 in words is "one million, six hundred eighty-eight thousand, four hundred thirty-six".