6421988 has 12 divisors (see below), whose sum is σ = 11899692. Its totient is φ = 3022080.

The previous prime is 6421967. The next prime is 6421997. The reversal of 6421988 is 8891246.

It can be written as a sum of positive squares in 2 ways, for example, as 5484964 + 937024 = 2342^2 + 968^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47153 + ... + 47288.

It is an arithmetic number, because the mean of its divisors is an integer number (991641).

Almost surely, 2^6421988 is an apocalyptic number.

6421988 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

6421988 is a deficient number, since it is larger than the sum of its proper divisors (5477704).

6421988 is a wasteful number, since it uses less digits than its factorization.

6421988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94462 (or 94460 counting only the distinct ones).

The product of its digits is 27648, while the sum is 38.

The square root of 6421988 is about 2534.1641620069. The cubic root of 6421988 is about 185.8759337586.

The spelling of 6421988 in words is "six million, four hundred twenty-one thousand, nine hundred eighty-eight".