6721630 has 32 divisors (see below), whose sum is σ = 13491360. Its totient is φ = 2396160.

The previous prime is 6721609. The next prime is 6721661. The reversal of 6721630 is 361276.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 6721595 and 6721604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2190 + ... + 4270.

It is an arithmetic number, because the mean of its divisors is an integer number (421605).

Almost surely, 2^6721630 is an apocalyptic number.

6721630 is an abundant number, since it is smaller than the sum of its proper divisors (6769730).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6721630 is a wasteful number, since it uses less digits than its factorization.

6721630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2124.

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 6721630 is about 2592.6106533762. The cubic root of 6721630 is about 188.7230156006.

The spelling of 6721630 in words is "six million, seven hundred twenty-one thousand, six hundred thirty".