6538427991225 has 567 divisors, whose sum is σ = 13896766267389. Its totient is φ = 3048803971200.

The previous prime is 6538427991203. The next prime is 6538427991241. The reversal of 6538427991225 is 5221997248356.

The square root of 6538427991225 is 2557035.

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

6538427991225 is a `hidden beast` number, since 6 + 5 + 384 + 27 + 9 + 9 + 1 + 225 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1685289486969 + 4853138504256 = 1298187^2 + 2202984^2 .

It is not a de Polignac number, because 6538427991225 - 2⁹ = 6538427990713 is a prime.

Its product of digits (65318400) is a multiple of the sum of its prime factors (210).

It is an unprimeable number.

It is a polite number, since it can be written in 566 ways as a sum of consecutive naturals, for example, 139115489152 + ... + 139115489198.

Almost surely, 2^{6538427991225} is an apocalyptic number.

6538427991225 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

6538427991225 is the 2557035-th square number.

6538427991225 is the 1278518-th centered octagonal number.

It is an amenable number.

6538427991225 is an abundant number, since it is smaller than the sum of its proper divisors (7358338276164).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6538427991225 is an equidigital number, since it uses as much as digits as its factorization.

6538427991225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210 (or 99 counting only the distinct ones).

The product of its digits is 65318400, while the sum is 63.

The spelling of 6538427991225 in words is "six trillion, five hundred thirty-eight billion, four hundred twenty-seven million, nine hundred ninety-one thousand, two hundred twenty-five".