1981447 has 4 divisors (see below), whose sum is σ = 2133880. Its totient is φ = 1829016.

The previous prime is 1981429. The next prime is 1981457. The reversal of 1981447 is 7441891.

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

It is a cyclic number.

It is not a de Polignac number, because 1981447 - 2¹¹ = 1979399 is a prime.

It is a super-3 number, since 3×1981447³ = 23338268689965604869, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981417) 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, 76197 + ... + 76222.

It is an arithmetic number, because the mean of its divisors is an integer number (533470).

2^1981447 is an apocalyptic number.

1981447 is a deficient number, since it is larger than the sum of its proper divisors (152433).

1981447 is a wasteful number, since it uses less digits than its factorization.

1981447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152432.

The product of its digits is 8064, while the sum is 34.

The square root of 1981447 is about 1407.6388031026. The cubic root of 1981447 is about 125.6013054823.

The spelling of 1981447 in words is "one million, nine hundred eighty-one thousand, four hundred forty-seven".