1989421 has 8 divisors (see below), whose sum is σ = 2312640. Its totient is φ = 1675968.

The previous prime is 1989419. The next prime is 1989479. The reversal of 1989421 is 1249891.

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

It is not a de Polignac number, because 1989421 - 2¹ = 1989419 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 (1989401) 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, 1996 + ... + 2821.

It is an arithmetic number, because the mean of its divisors is an integer number (289080).

2^1989421 is an apocalyptic number.

It is an amenable number.

1989421 is a deficient number, since it is larger than the sum of its proper divisors (323219).

1989421 is an equidigital number, since it uses as much as digits as its factorization.

1989421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4883.

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

The square root of 1989421 is about 1410.4683619281. The cubic root of 1989421 is about 125.7695670758.

The spelling of 1989421 in words is "one million, nine hundred eighty-nine thousand, four hundred twenty-one".