1986506 has 4 divisors (see below), whose sum is σ = 2979762. Its totient is φ = 993252.

The previous prime is 1986499. The next prime is 1986527. The reversal of 1986506 is 6056891.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1985281 + 1225 = 1409^2 + 35^2 .

It is an Ulam number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 496625 + ... + 496628.

2^1986506 is an apocalyptic number.

1986506 is a deficient number, since it is larger than the sum of its proper divisors (993256).

1986506 is an equidigital number, since it uses as much as digits as its factorization.

1986506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 993255.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 1986506 is about 1409.4346384278. The cubic root of 1986506 is about 125.7081090777.

The spelling of 1986506 in words is "one million, nine hundred eighty-six thousand, five hundred six".