2561819400 has 960 divisors, whose sum is σ = 11343024000. Its totient is φ = 522547200.

The previous prime is 2561819387. The next prime is 2561819411. The reversal of 2561819400 is 49181652.

2561819400 is a `hidden beast` number, since 2 + 561 + 8 + 1 + 94 + 0 + 0 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 62483380 + ... + 62483420.

It is an arithmetic number, because the mean of its divisors is an integer number (11815650).

It is a vampire number, since it can be written as 26100 ⋅ 98154 (with its own digits).

Almost surely, 2^2561819400 is an apocalyptic number.

2561819400 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 2561819400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5671512000).

2561819400 is an abundant number, since it is smaller than the sum of its proper divisors (8781204600).

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

2561819400 is a wasteful number, since it uses less digits than its factorization.

2561819400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 2561819400 is about 50614.4188942242. The cubic root of 2561819400 is about 1368.3047566641.

The spelling of 2561819400 in words is "two billion, five hundred sixty-one million, eight hundred nineteen thousand, four hundred".