261755570643 has 16 divisors (see below), whose sum is σ = 400305588480. Its totient is φ = 149034627936.

The previous prime is 261755570641. The next prime is 261755570647. The reversal of 261755570643 is 346075557162.

It is not a de Polignac number, because 261755570643 - 2¹ = 261755570641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261755570641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22493373 + ... + 22505006.

It is an arithmetic number, because the mean of its divisors is an integer number (25019099280).

Almost surely, 2^261755570643 is an apocalyptic number.

261755570643 is a deficient number, since it is larger than the sum of its proper divisors (138550017837).

261755570643 is a wasteful number, since it uses less digits than its factorization.

261755570643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44998666.

The product of its (nonzero) digits is 5292000, while the sum is 51.

The spelling of 261755570643 in words is "two hundred sixty-one billion, seven hundred fifty-five million, five hundred seventy thousand, six hundred forty-three".