6421989 has 24 divisors (see below), whose sum is σ = 10113600. Its totient is φ = 3623256.

The previous prime is 6421967. The next prime is 6421997. The reversal of 6421989 is 9891246.

It is not a de Polignac number, because 6421989 - 2⁹ = 6421477 is a prime.

It is a super-2 number, since 2×6421989² = 82483885432242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6421589) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81252 + ... + 81330.

It is an arithmetic number, because the mean of its divisors is an integer number (421400).

Almost surely, 2^6421989 is an apocalyptic number.

It is an amenable number.

6421989 is a deficient number, since it is larger than the sum of its proper divisors (3691611).

6421989 is an frugal number, since it uses more digits than its factorization.

6421989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182 (or 89 counting only the distinct ones).

The product of its digits is 31104, while the sum is 39.

The square root of 6421989 is about 2534.1643593106. The cubic root of 6421989 is about 185.8759434064.

The spelling of 6421989 in words is "six million, four hundred twenty-one thousand, nine hundred eighty-nine".