2561401233688 has 128 divisors (see below), whose sum is σ = 5689564416000. Its totient is φ = 1069423488000.

The previous prime is 2561401233679. The next prime is 2561401233689. The reversal of 2561401233688 is 8863321041652.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561401233689) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4393228 + ... + 4941988.

It is an arithmetic number, because the mean of its divisors is an integer number (44449722000).

Almost surely, 2^{2561401233688} 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 2561401233688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2844782208000).

2561401233688 is an abundant number, since it is smaller than the sum of its proper divisors (3128163182312).

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

2561401233688 is a wasteful number, since it uses less digits than its factorization.

2561401233688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548897 (or 548893 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 49.

The spelling of 2561401233688 in words is "two trillion, five hundred sixty-one billion, four hundred one million, two hundred thirty-three thousand, six hundred eighty-eight".