2015561025 has 81 divisors (see below), whose sum is σ = 3751675707. Its totient is φ = 1034380800.

The previous prime is 2015561011. The next prime is 2015561027. The reversal of 2015561025 is 5201655102.

The square root of 2015561025 is 44895.

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

2015561025 is a `hidden beast` number, since 2 + 0 + 1 + 556 + 102 + 5 = 666.

It can be written as a sum of positive squares in 13 ways, for example, as 1972159281 + 43401744 = 44409^2 + 6588^2 .

It is not a de Polignac number, because 2015561025 - 2⁹ = 2015560513 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2015561025.

It is not an unprimeable number, because it can be changed into a prime (2015561027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 27610389 + ... + 27610461.

Almost surely, 2^2015561025 is an apocalyptic number.

2015561025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

2015561025 is the 44895-th square number.

2015561025 is the 22448-th centered octagonal number.

It is an amenable number.

2015561025 is a deficient number, since it is larger than the sum of its proper divisors (1736114682).

2015561025 is an equidigital number, since it uses as much as digits as its factorization.

2015561025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The cubic root of 2015561025 is about 1263.1802222684.

The spelling of 2015561025 in words is "two billion, fifteen million, five hundred sixty-one thousand, twenty-five".