6421987 has 8 divisors (see below), whose sum is σ = 7544880. Its totient is φ = 5388960.

The previous prime is 6421967. The next prime is 6421997. The reversal of 6421987 is 7891246.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6421987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6421907) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22312 + ... + 22597.

It is an arithmetic number, because the mean of its divisors is an integer number (943110).

Almost surely, 2^6421987 is an apocalyptic number.

6421987 is a deficient number, since it is larger than the sum of its proper divisors (1122893).

6421987 is a wasteful number, since it uses less digits than its factorization.

6421987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44933.

The product of its digits is 24192, while the sum is 37.

The square root of 6421987 is about 2534.1639647032. The cubic root of 6421987 is about 185.8759241107.

The spelling of 6421987 in words is "six million, four hundred twenty-one thousand, nine hundred eighty-seven".