1986563 has 4 divisors (see below), whose sum is σ = 1995048. Its totient is φ = 1978080.

The previous prime is 1986553. The next prime is 1986577. The reversal of 1986563 is 3656891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3656891 = 7 ⋅522413.

It is a cyclic number.

It is not a de Polignac number, because 1986563 - 2⁴ = 1986547 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1986553) 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, 3881 + ... + 4362.

It is an arithmetic number, because the mean of its divisors is an integer number (498762).

2^1986563 is an apocalyptic number.

1986563 is a deficient number, since it is larger than the sum of its proper divisors (8485).

1986563 is an equidigital number, since it uses as much as digits as its factorization.

1986563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8484.

The product of its digits is 38880, while the sum is 38.

The square root of 1986563 is about 1409.4548591565. The cubic root of 1986563 is about 125.7093114054.

The spelling of 1986563 in words is "one million, nine hundred eighty-six thousand, five hundred sixty-three".