261656341055415 has 40 divisors (see below), whose sum is σ = 469053352263408. Its totient is φ = 139547033642880.

The previous prime is 261656341055411. The next prime is 261656341055429. The reversal of 261656341055415 is 514550143656162.

261656341055415 is a `hidden beast` number, since 2 + 6 + 1 + 6 + 5 + 63 + 4 + 10 + 554 + 15 = 666.

It is not a de Polignac number, because 261656341055415 - 2² = 261656341055411 is a prime.

It is a super-2 number, since 2×261656341055415² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261656341055411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11852844 + ... + 25764366.

Almost surely, 2^{261656341055415} is an apocalyptic number.

261656341055415 is a deficient number, since it is larger than the sum of its proper divisors (207397011207993).

261656341055415 is a wasteful number, since it uses less digits than its factorization.

261656341055415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13957981 (or 13957972 counting only the distinct ones).

The product of its (nonzero) digits is 12960000, while the sum is 54.

The spelling of 261656341055415 in words is "two hundred sixty-one trillion, six hundred fifty-six billion, three hundred forty-one million, fifty-five thousand, four hundred fifteen".