261620758560 has 192 divisors, whose sum is σ = 947280966912. Its totient is φ = 59453239296.

The previous prime is 261620758559. The next prime is 261620758573. The reversal of 261620758560 is 65857026162.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 356242 + ... + 806318.

It is an arithmetic number, because the mean of its divisors is an integer number (4933755036).

Almost surely, 2^261620758560 is an apocalyptic number.

261620758560 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 261620758560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (473640483456).

261620758560 is an abundant number, since it is smaller than the sum of its proper divisors (685660208352).

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

261620758560 is a wasteful number, since it uses less digits than its factorization.

261620758560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450275 (or 450267 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 48.

The spelling of 261620758560 in words is "two hundred sixty-one billion, six hundred twenty million, seven hundred fifty-eight thousand, five hundred sixty".