1688561 has 8 divisors (see below), whose sum is σ = 1937664. Its totient is φ = 1441440.

The previous prime is 1688543. The next prime is 1688573. The reversal of 1688561 is 1658861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1688561 - 2⁶ = 1688497 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2981 + ... + 3501.

It is an arithmetic number, because the mean of its divisors is an integer number (242208).

2^1688561 is an apocalyptic number.

It is an amenable number.

1688561 is a deficient number, since it is larger than the sum of its proper divisors (249103).

1688561 is an equidigital number, since it uses as much as digits as its factorization.

1688561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 991.

The product of its digits is 11520, while the sum is 35.

The square root of 1688561 is about 1299.4464205961. The cubic root of 1688561 is about 119.0800252629.

The spelling of 1688561 in words is "one million, six hundred eighty-eight thousand, five hundred sixty-one".