261954863280 has 480 divisors, whose sum is σ = 1024854405120. Its totient is φ = 59334912000.

The previous prime is 261954863257. The next prime is 261954863329. The reversal of 261954863280 is 82368459162.

261954863280 is a `hidden beast` number, since 2 + 6 + 19 + 548 + 6 + 3 + 2 + 80 = 666.

261954863280 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7101685 + ... + 7138475.

It is an arithmetic number, because the mean of its divisors is an integer number (2135113344).

Almost surely, 2^261954863280 is an apocalyptic number.

261954863280 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 261954863280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (512427202560).

261954863280 is an abundant number, since it is smaller than the sum of its proper divisors (762899541840).

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

261954863280 is a wasteful number, since it uses less digits than its factorization.

261954863280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36881 (or 36872 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 54.

The spelling of 261954863280 in words is "two hundred sixty-one billion, nine hundred fifty-four million, eight hundred sixty-three thousand, two hundred eighty".