6715556090721 has 27 divisors (see below), whose sum is σ = 9911566462161. Its totient is φ = 4381542866664.

The previous prime is 6715556090707. The next prime is 6715556090797. The reversal of 6715556090721 is 1270906555176.

The square root of 6715556090721 is 2591439.

It is a perfect power (a square), and thus also a powerful number.

6715556090721 is a `hidden beast` number, since 6 + 7 + 1 + 5 + 5 + 5 + 609 + 0 + 7 + 21 = 666.

It is not a de Polignac number, because 6715556090721 - 2⁹ = 6715556090209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6715556090921) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 365383710 + ... + 365402088.

Almost surely, 2^{6715556090721} is an apocalyptic number.

6715556090721 is the 2591439-th square number.

6715556090721 is the 1295720-th centered octagonal number.

It is an amenable number.

6715556090721 is a deficient number, since it is larger than the sum of its proper divisors (3196010371440).

6715556090721 is an frugal number, since it uses more digits than its factorization.

6715556090721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36858 (or 18429 counting only the distinct ones).

The product of its (nonzero) digits is 3969000, while the sum is 54.

The spelling of 6715556090721 in words is "six trillion, seven hundred fifteen billion, five hundred fifty-six million, ninety thousand, seven hundred twenty-one".