261753216818261 has 16 divisors (see below), whose sum is σ = 320752798410240. Its totient is φ = 208489318951680.

The previous prime is 261753216818189. The next prime is 261753216818267. The reversal of 261753216818261 is 162818612357162.

It is a cyclic number.

It is not a de Polignac number, because 261753216818261 - 2¹⁴ = 261753216801877 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261753216818261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261753216818267) 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, 13921553030 + ... + 13921571831.

It is an arithmetic number, because the mean of its divisors is an integer number (20047049900640).

Almost surely, 2^{261753216818261} is an apocalyptic number.

It is an amenable number.

261753216818261 is a deficient number, since it is larger than the sum of its proper divisors (58999581591979).

261753216818261 is a wasteful number, since it uses less digits than its factorization.

261753216818261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27843124964.

The product of its digits is 11612160, while the sum is 59.

The spelling of 261753216818261 in words is "two hundred sixty-one trillion, seven hundred fifty-three billion, two hundred sixteen million, eight hundred eighteen thousand, two hundred sixty-one".