261662717184064 has 567 divisors, whose sum is σ = 667404491462541. Its totient is φ = 101466174458880.

The previous prime is 261662717184053. The next prime is 261662717184073. The reversal of 261662717184064 is 460481717266162.

The square root of 261662717184064 is 16175992.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 207763626624064 + 53899090560000 = 14414008^2 + 7341600^2 .

It is a junction number, because it is equal to n+sod(n) for n = 261662717183993 and 261662717184011.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 395858875894 + ... + 395858876554.

Almost surely, 2^{261662717184064} is an apocalyptic number.

261662717184064 is the 16175992-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261662717184064

261662717184064 is an abundant number, since it is smaller than the sum of its proper divisors (405741774278477).

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

261662717184064 is an frugal number, since it uses more digits than its factorization.

261662717184064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1432 (or 712 counting only the distinct ones).

The product of its (nonzero) digits is 32514048, while the sum is 61.

The spelling of 261662717184064 in words is "two hundred sixty-one trillion, six hundred sixty-two billion, seven hundred seventeen million, one hundred eighty-four thousand, sixty-four".