2005120400 has 60 divisors (see below), whose sum is σ = 4861602900. Its totient is φ = 794672640.

The previous prime is 2005120399. The next prime is 2005120421. The reversal of 2005120400 is 40215002.

It can be written as a sum of positive squares in 6 ways, for example, as 290497936 + 1714622464 = 17044^2 + 41408^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20606 + ... + 66594.

It is an arithmetic number, because the mean of its divisors is an integer number (81026715).

Almost surely, 2^2005120400 is an apocalyptic number.

2005120400 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 2005120400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2430801450).

2005120400 is an abundant number, since it is smaller than the sum of its proper divisors (2856482500).

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

2005120400 is a wasteful number, since it uses less digits than its factorization.

2005120400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46116 (or 46105 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 2005120400 is about 44778.5707677233. The cubic root of 2005120400 is about 1260.9953502319.

Adding to 2005120400 its reverse (40215002), we get a palindrome (2045335402).

The spelling of 2005120400 in words is "two billion, five million, one hundred twenty thousand, four hundred".