261816769888 has 96 divisors (see below), whose sum is σ = 548921772000. Its totient is φ = 122498555904.

The previous prime is 261816769873. The next prime is 261816769919. The reversal of 261816769888 is 888967618162.

It is a congruent number.

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, 154099663 + ... + 154101361.

It is an arithmetic number, because the mean of its divisors is an integer number (5717935125).

Almost surely, 2^261816769888 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 261816769888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274460886000).

261816769888 is an abundant number, since it is smaller than the sum of its proper divisors (287105002112).

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

261816769888 is a wasteful number, since it uses less digits than its factorization.

261816769888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3192 (or 3184 counting only the distinct ones).

The product of its digits is 111476736, while the sum is 70.

The spelling of 261816769888 in words is "two hundred sixty-one billion, eight hundred sixteen million, seven hundred sixty-nine thousand, eight hundred eighty-eight".