1988647 has 4 divisors (see below), whose sum is σ = 1999816. Its totient is φ = 1977480.

The previous prime is 1988633. The next prime is 1988653. The reversal of 1988647 is 7468891.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1988647 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 (1988347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5313 + ... + 5674.

It is an arithmetic number, because the mean of its divisors is an integer number (499954).

2^1988647 is an apocalyptic number.

1988647 is a deficient number, since it is larger than the sum of its proper divisors (11169).

1988647 is a wasteful number, since it uses less digits than its factorization.

1988647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11168.

The product of its digits is 96768, while the sum is 43.

The square root of 1988647 is about 1410.1939582908. The cubic root of 1988647 is about 125.7532544113.

The spelling of 1988647 in words is "one million, nine hundred eighty-eight thousand, six hundred forty-seven".