261028836 has 18 divisors (see below), whose sum is σ = 659822982. Its totient is φ = 87009600.

The previous prime is 261028793. The next prime is 261028871. The reversal of 261028836 is 638820162.

261028836 is a `hidden beast` number, since 2 + 610 + 2 + 8 + 8 + 36 = 666.

It can be written as a sum of positive squares in only one way, i.e., 221414400 + 39614436 = 14880^2 + 6294^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 7250801 = 261028836 / (2 + 6 + 1 + 0 + 2 + 8 + 8 + 3 + 6).

It is a self number, because there is not a number n which added to its sum of digits gives 261028836.

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 5 ways as a sum of consecutive naturals, for example, 3625365 + ... + 3625436.

Almost surely, 2^261028836 is an apocalyptic number.

It is an amenable number.

261028836 is an abundant number, since it is smaller than the sum of its proper divisors (398794146).

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

261028836 is a wasteful number, since it uses less digits than its factorization.

261028836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7250811 (or 7250806 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 261028836 is about 16156.3868485500. The cubic root of 261028836 is about 639.0911872923.

Adding to 261028836 its reverse (638820162), we get a palindrome (899848998).

The spelling of 261028836 in words is "two hundred sixty-one million, twenty-eight thousand, eight hundred thirty-six".