66121048305225 has 81 divisors (see below), whose sum is σ = 119795439103509. Its totient is φ = 34862603529600.

The previous prime is 66121048305199. The next prime is 66121048305227. The reversal of 66121048305225 is 52250384012166.

The square root of 66121048305225 is 8131485.

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

66121048305225 is a `hidden beast` number, since 6 + 6 + 12 + 104 + 8 + 3 + 0 + 522 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 13759789317561 + 52361258987664 = 3709419^2 + 7236108^2 .

It is not a de Polignac number, because 66121048305225 - 2⁷ = 66121048305097 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (66121048305227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 10855529430 + ... + 10855535520.

Almost surely, 2^{66121048305225} is an apocalyptic number.

66121048305225 is the 8131485-th square number.

66121048305225 is the 4065743-rd centered octagonal number.

It is an amenable number.

66121048305225 is a deficient number, since it is larger than the sum of its proper divisors (53674390798284).

66121048305225 is an frugal number, since it uses more digits than its factorization.

66121048305225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12376 (or 6188 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The spelling of 66121048305225 in words is "sixty-six trillion, one hundred twenty-one billion, forty-eight million, three hundred five thousand, two hundred twenty-five".