6921555883225 has 27 divisors (see below), whose sum is σ = 8821584614871. Its totient is φ = 5387210596800.

The previous prime is 6921555883181. The next prime is 6921555883261. The reversal of 6921555883225 is 5223885551296.

It is a happy number.

The square root of 6921555883225 is 2630885.

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

It can be written as a sum of positive squares in 13 ways, for example, as 538070662089 + 6383485221136 = 733533^2 + 2526556^2 .

It is not a de Polignac number, because 6921555883225 - 2⁷ = 6921555883097 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 486706615 + ... + 486720835.

Almost surely, 2^{6921555883225} is an apocalyptic number.

6921555883225 is the 2630885-th square number.

6921555883225 is the 1315443-rd centered octagonal number.

It is an amenable number.

6921555883225 is a deficient number, since it is larger than the sum of its proper divisors (1900028731646).

6921555883225 is an frugal number, since it uses more digits than its factorization.

6921555883225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28526 (or 14263 counting only the distinct ones).

The product of its digits is 51840000, while the sum is 61.

The spelling of 6921555883225 in words is "six trillion, nine hundred twenty-one billion, five hundred fifty-five million, eight hundred eighty-three thousand, two hundred twenty-five".