6643725416 has 16 divisors (see below), whose sum is σ = 12503297700. Its totient is φ = 3309512704.

The previous prime is 6643725379. The next prime is 6643725433. The reversal of 6643725416 is 6145273466.

It can be written as a sum of positive squares in 2 ways, for example, as 4729312900 + 1914412516 = 68770^2 + 43754^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1541465 + ... + 1545768.

Almost surely, 2^6643725416 is an apocalyptic number.

It is an amenable number.

6643725416 is a deficient number, since it is larger than the sum of its proper divisors (5859572284).

6643725416 is a wasteful number, since it uses less digits than its factorization.

6643725416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3087508 (or 3087504 counting only the distinct ones).

The product of its digits is 725760, while the sum is 44.

The square root of 6643725416 is about 81509.0511293071. The cubic root of 6643725416 is about 1879.9107223335.

The spelling of 6643725416 in words is "six billion, six hundred forty-three million, seven hundred twenty-five thousand, four hundred sixteen".