261656341057641 has 8 divisors (see below), whose sum is σ = 356988496326880. Its totient is φ = 170380873246752.

The previous prime is 261656341057591. The next prime is 261656341057669. The reversal of 261656341057641 is 146750143656162.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-261656341057641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261656341053641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1014171864436 + ... + 1014171864693.

It is an arithmetic number, because the mean of its divisors is an integer number (44623562040860).

Almost surely, 2^{261656341057641} is an apocalyptic number.

It is an amenable number.

261656341057641 is a deficient number, since it is larger than the sum of its proper divisors (95332155269239).

261656341057641 is a wasteful number, since it uses less digits than its factorization.

261656341057641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2028343729175.

The product of its (nonzero) digits is 21772800, while the sum is 57.

The spelling of 261656341057641 in words is "two hundred sixty-one trillion, six hundred fifty-six billion, three hundred forty-one million, fifty-seven thousand, six hundred forty-one".