6721654 has 4 divisors (see below), whose sum is σ = 10082484. Its totient is φ = 3360826.

The previous prime is 6721609. The next prime is 6721661. The reversal of 6721654 is 4561276.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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

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 as a sum of consecutive naturals, namely, 1680412 + ... + 1680415.

It is an arithmetic number, because the mean of its divisors is an integer number (2520621).

Almost surely, 2^6721654 is an apocalyptic number.

6721654 is a deficient number, since it is larger than the sum of its proper divisors (3360830).

6721654 is a wasteful number, since it uses less digits than its factorization.

6721654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3360829.

The product of its digits is 10080, while the sum is 31.

The square root of 6721654 is about 2592.6152819113. The cubic root of 6721654 is about 188.7232402161.

The spelling of 6721654 in words is "six million, seven hundred twenty-one thousand, six hundred fifty-four".