2581656000 has 672 divisors, whose sum is σ = 10792943616. Its totient is φ = 532224000.

The previous prime is 2581655981. The next prime is 2581656001. The reversal of 2581656000 is 6561852.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2581656001) 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, 20327937 + ... + 20328063.

It is an arithmetic number, because the mean of its divisors is an integer number (16060928).

Almost surely, 2^2581656000 is an apocalyptic number.

2581656000 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 2581656000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5396471808).

2581656000 is an abundant number, since it is smaller than the sum of its proper divisors (8211287616).

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

2581656000 is a wasteful number, since it uses less digits than its factorization.

2581656000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 33.

The square root of 2581656000 is about 50809.9990159417. Note that the first 3 decimals coincide. The cubic root of 2581656000 is about 1371.8273517904.

The spelling of 2581656000 in words is "two billion, five hundred eighty-one million, six hundred fifty-six thousand".