1671986 has 4 divisors (see below), whose sum is σ = 2507982. Its totient is φ = 835992.

The previous prime is 1671983. The next prime is 1671997. The reversal of 1671986 is 6891761.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6891761 = 557 ⋅12373.

It can be written as a sum of positive squares in only one way, i.e., 1452025 + 219961 = 1205^2 + 469^2 .

It is not an unprimeable number, because it can be changed into a prime (1671983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 417995 + ... + 417998.

2^1671986 is an apocalyptic number.

1671986 is a deficient number, since it is larger than the sum of its proper divisors (835996).

1671986 is an equidigital number, since it uses as much as digits as its factorization.

1671986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 835995.

The product of its digits is 18144, while the sum is 38.

The square root of 1671986 is about 1293.0529764863. The cubic root of 1671986 is about 118.6891115367.

The spelling of 1671986 in words is "one million, six hundred seventy-one thousand, nine hundred eighty-six".