1687081 has 4 divisors (see below), whose sum is σ = 1840464. Its totient is φ = 1533700.

The previous prime is 1687061. The next prime is 1687087. The reversal of 1687081 is 1807861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1687081 - 2⁹ = 1686569 is a prime.

It is a super-2 number, since 2×1687081² = 5692484601122, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

1687081 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1687087) 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, 76675 + ... + 76696.

It is an arithmetic number, because the mean of its divisors is an integer number (460116).

2^1687081 is an apocalyptic number.

1687081 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1687081 is a deficient number, since it is larger than the sum of its proper divisors (153383).

1687081 is a wasteful number, since it uses less digits than its factorization.

1687081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153382.

The product of its (nonzero) digits is 2688, while the sum is 31.

The square root of 1687081 is about 1298.8768224893. The cubic root of 1687081 is about 119.0452244369.

The spelling of 1687081 in words is "one million, six hundred eighty-seven thousand, eighty-one".