1428639 has 8 divisors (see below), whose sum is σ = 1910832. Its totient is φ = 949440.

The previous prime is 1428631. The next prime is 1428649. The reversal of 1428639 is 9368241.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1428639 - 2³ = 1428631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1428631) 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 in 7 ways as a sum of consecutive naturals, for example, 867 + ... + 1899.

It is an arithmetic number, because the mean of its divisors is an integer number (238854).

2^1428639 is an apocalyptic number.

1428639 is a deficient number, since it is larger than the sum of its proper divisors (482193).

1428639 is a wasteful number, since it uses less digits than its factorization.

1428639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1497.

The product of its digits is 10368, while the sum is 33.

The square root of 1428639 is about 1195.2568761568. The cubic root of 1428639 is about 112.6265637339.

The spelling of 1428639 in words is "one million, four hundred twenty-eight thousand, six hundred thirty-nine".