261840764395560 has 256 divisors, whose sum is σ = 909624340684800. Its totient is φ = 59057880440832.

The previous prime is 261840764395559. The next prime is 261840764395601. The reversal of 261840764395560 is 65593467048162.

261840764395560 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×261840764395560² (a number of 30 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 261840764395491 and 261840764395500.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 114801624 + ... + 117060216.

It is an arithmetic number, because the mean of its divisors is an integer number (3553220080800).

It is a 1-persistent number, because it is pandigital, but 2⋅261840764395560 = 523681528791120 is not.

Almost surely, 2^{261840764395560} is an apocalyptic number.

261840764395560 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 261840764395560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (454812170342400).

261840764395560 is an abundant number, since it is smaller than the sum of its proper divisors (647783576289240).

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

261840764395560 is a wasteful number, since it uses less digits than its factorization.

261840764395560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2260440 (or 2260436 counting only the distinct ones).

The product of its (nonzero) digits is 261273600, while the sum is 66.

The spelling of 261840764395560 in words is "two hundred sixty-one trillion, eight hundred forty billion, seven hundred sixty-four million, three hundred ninety-five thousand, five hundred sixty".