261945881088 has 80 divisors (see below), whose sum is σ = 700621469856. Its totient is φ = 86967296000.

The previous prime is 261945881069. The next prime is 261945881101. The reversal of 261945881088 is 880188549162.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45820 + ... + 725252.

Almost surely, 2^261945881088 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 261945881088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (350310734928).

261945881088 is an abundant number, since it is smaller than the sum of its proper divisors (438675588768).

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

261945881088 is an equidigital number, since it uses as much as digits as its factorization.

261945881088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679705 (or 679689 counting only the distinct ones).

The product of its (nonzero) digits is 8847360, while the sum is 60.

The spelling of 261945881088 in words is "two hundred sixty-one billion, nine hundred forty-five million, eight hundred eighty-one thousand, eighty-eight".