6743656721 has 4 divisors (see below), whose sum is σ = 6745677312. Its totient is φ = 6741636132.

The previous prime is 6743656669. The next prime is 6743656763. The reversal of 6743656721 is 1276563476.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6743656721 - 2²² = 6739462417 is a prime.

It is a super-3 number, since 3×6743656721³ (a number of 30 digits) contains 333 as substring.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6743656421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1005281 + ... + 1011966.

It is an arithmetic number, because the mean of its divisors is an integer number (1686419328).

Almost surely, 2^6743656721 is an apocalyptic number.

It is an amenable number.

6743656721 is a deficient number, since it is larger than the sum of its proper divisors (2020591).

6743656721 is a wasteful number, since it uses less digits than its factorization.

6743656721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2020590.

The product of its digits is 1270080, while the sum is 47.

The square root of 6743656721 is about 82119.7705854078. The cubic root of 6743656721 is about 1889.2893870249.

The spelling of 6743656721 in words is "six billion, seven hundred forty-three million, six hundred fifty-six thousand, seven hundred twenty-one".