261571542105321 has 48 divisors (see below), whose sum is σ = 457511490828288. Its totient is φ = 140581497369600.

The previous prime is 261571542105299. The next prime is 261571542105359. The reversal of 261571542105321 is 123501245175162.

261571542105321 is a `hidden beast` number, since 2 + 6 + 1 + 5 + 71 + 5 + 42 + 1 + 0 + 532 + 1 = 666.

It is not a de Polignac number, because 261571542105321 - 2⁷ = 261571542105193 is a prime.

It is a super-3 number, since 3×261571542105321³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (261571542106321) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 81439900 + ... + 84590781.

It is an arithmetic number, because the mean of its divisors is an integer number (9531489392256).

Almost surely, 2^{261571542105321} is an apocalyptic number.

261571542105321 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

261571542105321 is a deficient number, since it is larger than the sum of its proper divisors (195939948722967).

261571542105321 is a wasteful number, since it uses less digits than its factorization.

261571542105321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166032182 (or 166032179 counting only the distinct ones).

The product of its (nonzero) digits is 504000, while the sum is 45.

The spelling of 261571542105321 in words is "two hundred sixty-one trillion, five hundred seventy-one billion, five hundred forty-two million, one hundred five thousand, three hundred twenty-one".