261021128625 has 96 divisors (see below), whose sum is σ = 477612495360. Its totient is φ = 137127091200.

The previous prime is 261021128611. The next prime is 261021128657. The reversal of 261021128625 is 526821120162.

261021128625 is a `hidden beast` number, since 2 + 6 + 1 + 0 + 2 + 1 + 1 + 28 + 625 = 666.

261021128625 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 261021128625 - 2⁵ = 261021128593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261021128625.

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 95 ways as a sum of consecutive naturals, for example, 32957416 + ... + 32965334.

It is an arithmetic number, because the mean of its divisors is an integer number (4975130160).

Almost surely, 2^261021128625 is an apocalyptic number.

261021128625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261021128625 is a deficient number, since it is larger than the sum of its proper divisors (216591366735).

261021128625 is a wasteful number, since it uses less digits than its factorization.

261021128625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8376 (or 8363 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

Adding to 261021128625 its reverse (526821120162), we get a palindrome (787842248787).

The spelling of 261021128625 in words is "two hundred sixty-one billion, twenty-one million, one hundred twenty-eight thousand, six hundred twenty-five".