6728781 has 8 divisors (see below), whose sum is σ = 8989344. Its totient is φ = 4477040.

The previous prime is 6728759. The next prime is 6728801. The reversal of 6728781 is 1878276.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6728781 - 2⁵ = 6728749 is a prime.

It is a super-2 number, since 2×6728781² = 90552987491922, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6728731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 150 + ... + 3671.

It is an arithmetic number, because the mean of its divisors is an integer number (1123668).

Almost surely, 2^6728781 is an apocalyptic number.

It is an amenable number.

6728781 is a deficient number, since it is larger than the sum of its proper divisors (2260563).

6728781 is a wasteful number, since it uses less digits than its factorization.

6728781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4411.

The product of its digits is 37632, while the sum is 39.

The square root of 6728781 is about 2593.9893985905. The cubic root of 6728781 is about 188.7899180225.

It can be divided in two parts, 672 and 8781, that added together give a triangular number (9453 = T₁₃₇).

The spelling of 6728781 in words is "six million, seven hundred twenty-eight thousand, seven hundred eighty-one".