2581191648 has 288 divisors, whose sum is σ = 8952652800. Its totient is φ = 689015808.

The previous prime is 2581191647. The next prime is 2581191703. The reversal of 2581191648 is 8461911852.

It is a happy number.

2581191648 is a `hidden beast` number, since 2 + 581 + 1 + 9 + 1 + 64 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2581191647) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3025590 + ... + 3026442.

It is an arithmetic number, because the mean of its divisors is an integer number (31085600).

Almost surely, 2^2581191648 is an apocalyptic number.

2581191648 is a gapful number since it is divisible by the number (28) 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 2581191648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4476326400).

2581191648 is an abundant number, since it is smaller than the sum of its proper divisors (6371461152).

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

2581191648 is a wasteful number, since it uses less digits than its factorization.

2581191648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 974 (or 963 counting only the distinct ones).

The product of its digits is 138240, while the sum is 45.

The square root of 2581191648 is about 50805.4293161666. The cubic root of 2581191648 is about 1371.7450985170.

The spelling of 2581191648 in words is "two billion, five hundred eighty-one million, one hundred ninety-one thousand, six hundred forty-eight".