1291984 has 10 divisors (see below), whose sum is σ = 2503250. Its totient is φ = 645984.

The previous prime is 1291967. The next prime is 1291991. The reversal of 1291984 is 4891921.

It can be written as a sum of positive squares in only one way, i.e., 1272384 + 19600 = 1128^2 + 140^2 .

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 40359 + ... + 40390.

It is an arithmetic number, because the mean of its divisors is an integer number (250325).

2^1291984 is an apocalyptic number.

It is an amenable number.

1291984 is a deficient number, since it is larger than the sum of its proper divisors (1211266).

1291984 is an equidigital number, since it uses as much as digits as its factorization.

1291984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80757 (or 80751 counting only the distinct ones).

The product of its digits is 5184, while the sum is 34.

The square root of 1291984 is about 1136.6547408954. The cubic root of 1291984 is about 108.9145024355.

The spelling of 1291984 in words is "one million, two hundred ninety-one thousand, nine hundred eighty-four".