261421716207546 has 96 divisors (see below), whose sum is σ = 598429168296960. Its totient is φ = 82249264759968.

The previous prime is 261421716207523. The next prime is 261421716207557. The reversal of 261421716207546 is 645702617124162.

261421716207546 is a `hidden beast` number, since 2 + 6 + 1 + 4 + 2 + 1 + 7 + 1 + 620 + 7 + 5 + 4 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 261421716207492 and 261421716207501.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 239576925 + ... + 240665631.

It is an arithmetic number, because the mean of its divisors is an integer number (6233637169760).

Almost surely, 2^{261421716207546} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261421716207546, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (299214584148480).

261421716207546 is an abundant number, since it is smaller than the sum of its proper divisors (337007452089414).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261421716207546 is a wasteful number, since it uses less digits than its factorization.

261421716207546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1091328 (or 1091325 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 54.

The spelling of 261421716207546 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, seven hundred sixteen million, two hundred seven thousand, five hundred forty-six".