2561097240 has 384 divisors, whose sum is σ = 9392947200. Its totient is φ = 600929280.

The previous prime is 2561097233. The next prime is 2561097241. The reversal of 2561097240 is 427901652.

2561097240 is a `hidden beast` number, since 2 + 561 + 0 + 97 + 2 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2561097195 and 2561097204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561097241) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 18425091 + ... + 18425229.

It is an arithmetic number, because the mean of its divisors is an integer number (24460800).

Almost surely, 2^2561097240 is an apocalyptic number.

2561097240 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 2561097240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4696473600).

2561097240 is an abundant number, since it is smaller than the sum of its proper divisors (6831849960).

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

2561097240 is a wasteful number, since it uses less digits than its factorization.

2561097240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327 (or 320 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 2561097240 is about 50607.2844558963. The cubic root of 2561097240 is about 1368.1761725509.

Adding to 2561097240 its reverse (427901652), we get a palindrome (2988998892).

The spelling of 2561097240 in words is "two billion, five hundred sixty-one million, ninety-seven thousand, two hundred forty".