6747281721 has 16 divisors (see below), whose sum is σ = 9997686400. Its totient is φ = 4497416784.

The previous prime is 6747281711. The next prime is 6747281743. The reversal of 6747281721 is 1271827476.

6747281721 is a `hidden beast` number, since 6 + 7 + 472 + 8 + 172 + 1 = 666.

It is not a de Polignac number, because 6747281721 - 2⁵ = 6747281689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6747281701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 170175 + ... + 206043.

It is an arithmetic number, because the mean of its divisors is an integer number (624855400).

Almost surely, 2^6747281721 is an apocalyptic number.

It is an amenable number.

6747281721 is a deficient number, since it is larger than the sum of its proper divisors (3250404679).

6747281721 is a wasteful number, since it uses less digits than its factorization.

6747281721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42845 (or 42839 counting only the distinct ones).

The product of its digits is 263424, while the sum is 45.

The square root of 6747281721 is about 82141.8390407714. The cubic root of 6747281721 is about 1889.6278506373.

The spelling of 6747281721 in words is "six billion, seven hundred forty-seven million, two hundred eighty-one thousand, seven hundred twenty-one".