261657755 has 4 divisors (see below), whose sum is σ = 313989312. Its totient is φ = 209326200.

The previous prime is 261657751. The next prime is 261657757. The reversal of 261657755 is 557756162.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 261657755 - 2² = 261657751 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261657751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26165771 + ... + 26165780.

It is an arithmetic number, because the mean of its divisors is an integer number (78497328).

Almost surely, 2^261657755 is an apocalyptic number.

261657755 is a deficient number, since it is larger than the sum of its proper divisors (52331557).

261657755 is an equidigital number, since it uses as much as digits as its factorization.

261657755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52331556.

The product of its digits is 441000, while the sum is 44.

The square root of 261657755 is about 16175.8386181366. The cubic root of 261657755 is about 639.6040478908.

The spelling of 261657755 in words is "two hundred sixty-one million, six hundred fifty-seven thousand, seven hundred fifty-five".