6909157728 has 72 divisors (see below), whose sum is σ = 21434101416. Its totient is φ = 2093683200.

The previous prime is 6909157711. The next prime is 6909157733. The reversal of 6909157728 is 8277519096.

6909157728 is a `hidden beast` number, since 69 + 0 + 9 + 1 + 577 + 2 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1087293 + ... + 1093628.

It is an arithmetic number, because the mean of its divisors is an integer number (297695853).

Almost surely, 2^6909157728 is an apocalyptic number.

It is an amenable number.

6909157728 is an abundant number, since it is smaller than the sum of its proper divisors (14524943688).

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

6909157728 is a wasteful number, since it uses less digits than its factorization.

6909157728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2180948 (or 2180937 counting only the distinct ones).

The product of its (nonzero) digits is 1905120, while the sum is 54.

The square root of 6909157728 is about 83121.3433962662. The cubic root of 6909157728 is about 1904.6201255483.

The spelling of 6909157728 in words is "six billion, nine hundred nine million, one hundred fifty-seven thousand, seven hundred twenty-eight".