261170782427520 has 2048 divisors, whose sum is σ = 1142748020736000. Its totient is φ = 55047045021696.

The previous prime is 261170782427459. The next prime is 261170782427561. The reversal of 261170782427520 is 25724287071162.

261170782427520 is a `hidden beast` number, since 2 + 6 + 1 + 1 + 7 + 0 + 78 + 2 + 42 + 7 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

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 255 ways as a sum of consecutive naturals, for example, 15469444999 + ... + 15469461881.

It is an arithmetic number, because the mean of its divisors is an integer number (557982432000).

Almost surely, 2^{261170782427520} is an apocalyptic number.

261170782427520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261170782427520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (571374010368000).

261170782427520 is an abundant number, since it is smaller than the sum of its proper divisors (881577238308480).

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

261170782427520 is a wasteful number, since it uses less digits than its factorization.

261170782427520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17117 (or 17099 counting only the distinct ones).

The product of its (nonzero) digits is 5268480, while the sum is 54.

The spelling of 261170782427520 in words is "two hundred sixty-one trillion, one hundred seventy billion, seven hundred eighty-two million, four hundred twenty-seven thousand, five hundred twenty".