2581333920 has 480 divisors, whose sum is σ = 10472172480. Its totient is φ = 592220160.

The previous prime is 2581333913. The next prime is 2581333921. The reversal of 2581333920 is 293331852.

2581333920 is a `hidden beast` number, since 258 + 13 + 3 + 392 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

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

It is not an unprimeable number, because it can be changed into a prime (2581333921) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2708164 + ... + 2709116.

It is an arithmetic number, because the mean of its divisors is an integer number (21817026).

Almost surely, 2^2581333920 is an apocalyptic number.

2581333920 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 2581333920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5236086240).

2581333920 is an abundant number, since it is smaller than the sum of its proper divisors (7890838560).

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

2581333920 is a wasteful number, since it uses less digits than its factorization.

2581333920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010 (or 993 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 2581333920 is about 50806.8294621894. The cubic root of 2581333920 is about 1371.7703010022.

The spelling of 2581333920 in words is "two billion, five hundred eighty-one million, three hundred thirty-three thousand, nine hundred twenty".