1681287 has 8 divisors (see below), whose sum is σ = 2296560. Its totient is φ = 1093440.

The previous prime is 1681279. The next prime is 1681289. The reversal of 1681287 is 7821861.

It is a happy number.

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

It is not a de Polignac number, because 1681287 - 2³ = 1681279 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

1681287 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681289) 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, 6712 + ... + 6957.

It is an arithmetic number, because the mean of its divisors is an integer number (287070).

2^1681287 is an apocalyptic number.

1681287 is a deficient number, since it is larger than the sum of its proper divisors (615273).

1681287 is a wasteful number, since it uses less digits than its factorization.

1681287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13713.

The product of its digits is 5376, while the sum is 33.

The square root of 1681287 is about 1296.6445156634. The cubic root of 1681287 is about 118.9087877654.

The spelling of 1681287 in words is "one million, six hundred eighty-one thousand, two hundred eighty-seven".