261155746432 has 128 divisors (see below), whose sum is σ = 609967572480. Its totient is φ = 109038182400.

The previous prime is 261155746373. The next prime is 261155746487. The reversal of 261155746432 is 234647551162.

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27804457 + ... + 27813847.

It is an arithmetic number, because the mean of its divisors is an integer number (4765371660).

Almost surely, 2^261155746432 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261155746432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (304983786240).

261155746432 is an abundant number, since it is smaller than the sum of its proper divisors (348811826048).

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

261155746432 is an equidigital number, since it uses as much as digits as its factorization.

261155746432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10210 (or 10198 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 46.

The spelling of 261155746432 in words is "two hundred sixty-one billion, one hundred fifty-five million, seven hundred forty-six thousand, four hundred thirty-two".