9781287525025 has 27 divisors (see below), whose sum is σ = 12562035180331. Its totient is φ = 7554851118080.

The previous prime is 9781287524969. The next prime is 9781287525049. The reversal of 9781287525025 is 5205257821879.

The square root of 9781287525025 is 3127505.

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 9760269484449 + 21018040576 = 3124143^2 + 144976^2 .

It is not a de Polignac number, because 9781287525025 - 2¹⁷ = 9781287393953 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 26 ways as a sum of consecutive naturals, for example, 453477441 + ... + 453499009.

Almost surely, 2^{9781287525025} is an apocalyptic number.

9781287525025 is the 3127505-th square number.

9781287525025 is the 1563753-rd centered octagonal number.

It is an amenable number.

9781287525025 is a deficient number, since it is larger than the sum of its proper divisors (2780747655306).

9781287525025 is an frugal number, since it uses more digits than its factorization.

9781287525025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43206 (or 21603 counting only the distinct ones).

The product of its (nonzero) digits is 28224000, while the sum is 61.

The spelling of 9781287525025 in words is "nine trillion, seven hundred eighty-one billion, two hundred eighty-seven million, five hundred twenty-five thousand, twenty-five".