261855653 has 2 divisors, whose sum is σ = 261855654. Its totient is φ = 261855652.

The previous prime is 261855637. The next prime is 261855673. The reversal of 261855653 is 356558162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 214974244 + 46881409 = 14662^2 + 6847^2 .

It is a cyclic number.

It is not a de Polignac number, because 261855653 - 2⁴ = 261855637 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261855653.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261855613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130927826 + 130927827.

It is an arithmetic number, because the mean of its divisors is an integer number (130927827).

Almost surely, 2^261855653 is an apocalyptic number.

It is an amenable number.

261855653 is a deficient number, since it is larger than the sum of its proper divisors (1).

261855653 is an equidigital number, since it uses as much as digits as its factorization.

261855653 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216000, while the sum is 41.

The square root of 261855653 is about 16181.9545481997. The cubic root of 261855653 is about 639.7652565204.

The spelling of 261855653 in words is "two hundred sixty-one million, eight hundred fifty-five thousand, six hundred fifty-three".