6921408025 has 27 divisors (see below), whose sum is σ = 9987979869. Its totient is φ = 4744111680.

The previous prime is 6921408017. The next prime is 6921408049. The reversal of 6921408025 is 5208041296.

The square root of 6921408025 is 83195.

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

It can be written as a sum of positive squares in 4 ways, for example, as 414081801 + 6507326224 = 20349^2 + 80668^2 .

It is not a de Polignac number, because 6921408025 - 2³ = 6921408017 is a prime.

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, 2910637 + ... + 2913013.

Almost surely, 2^6921408025 is an apocalyptic number.

6921408025 is the 83195-th square number.

6921408025 is the 41598-th centered octagonal number.

It is an amenable number.

6921408025 is a deficient number, since it is larger than the sum of its proper divisors (3066571844).

6921408025 is an frugal number, since it uses more digits than its factorization.

6921408025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4778 (or 2389 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The cubic root of 6921408025 is about 1905.7451245222.

The spelling of 6921408025 in words is "six billion, nine hundred twenty-one million, four hundred eight thousand, twenty-five".