1678987 has 8 divisors (see below), whose sum is σ = 1736640. Its totient is φ = 1622400.

The previous prime is 1678979. The next prime is 1678993. The reversal of 1678987 is 7898761.

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

It is a cyclic number.

It is not a de Polignac number, because 1678987 - 2³ = 1678979 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1678687) 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, 3987 + ... + 4387.

It is an arithmetic number, because the mean of its divisors is an integer number (217080).

2^1678987 is an apocalyptic number.

1678987 is a deficient number, since it is larger than the sum of its proper divisors (57653).

1678987 is an equidigital number, since it uses as much as digits as its factorization.

1678987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533.

The product of its digits is 169344, while the sum is 46.

The square root of 1678987 is about 1295.7573075233. The cubic root of 1678987 is about 118.8545406285.

It can be divided in two parts, 16 and 78987, that added together give a triangular number (79003 = T₃₉₇).

The spelling of 1678987 in words is "one million, six hundred seventy-eight thousand, nine hundred eighty-seven".