261268648342657 has 8 divisors (see below), whose sum is σ = 261535503853800. Its totient is φ = 261001802454144.

The previous prime is 261268648342643. The next prime is 261268648342687. The reversal of 261268648342657 is 756243846862162.

It can be written as a sum of positive squares in 4 ways, for example, as 218397530201841 + 42871118140816 = 14778279^2 + 6547604^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 261268648342657 - 2⁷ = 261268648342529 is a prime.

It is a super-2 number, since 2×261268648342657² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261268648342687) 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, 52566069 + ... + 57321277.

It is an arithmetic number, because the mean of its divisors is an integer number (32691937981725).

Almost surely, 2^{261268648342657} is an apocalyptic number.

It is an amenable number.

261268648342657 is a deficient number, since it is larger than the sum of its proper divisors (266855511143).

261268648342657 is an equidigital number, since it uses as much as digits as its factorization.

261268648342657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4811315.

The product of its digits is 1114767360, while the sum is 70.

The spelling of 261268648342657 in words is "two hundred sixty-one trillion, two hundred sixty-eight billion, six hundred forty-eight million, three hundred forty-two thousand, six hundred fifty-seven".