1984639 has 2 divisors, whose sum is σ = 1984640. Its totient is φ = 1984638.

The previous prime is 1984571. The next prime is 1984649. The reversal of 1984639 is 9364891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1984639 - 2⁷ = 1984511 is a prime.

It is a Chen prime.

1984639 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1984649) by changing a digit.

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, 992319 + 992320.

It is an arithmetic number, because the mean of its divisors is an integer number (992320).

2^1984639 is an apocalyptic number.

1984639 is a deficient number, since it is larger than the sum of its proper divisors (1).

1984639 is an equidigital number, since it uses as much as digits as its factorization.

1984639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 40.

The square root of 1984639 is about 1408.7721604291. The cubic root of 1984639 is about 125.6687148508.

The spelling of 1984639 in words is "one million, nine hundred eighty-four thousand, six hundred thirty-nine".