2561116500 has 72 divisors (see below), whose sum is σ = 8079483048. Its totient is φ = 682963200.

The previous prime is 2561116477. The next prime is 2561116501. The reversal of 2561116500 is 56111652.

It is a happy number.

2561116500 is a `hidden beast` number, since 2 + 5 + 6 + 1 + 1 + 1 + 650 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 523677456 + 2037439044 = 22884^2 + 45138^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561116501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 280069 + ... + 289068.

Almost surely, 2^2561116500 is an apocalyptic number.

2561116500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2561116500 is an abundant number, since it is smaller than the sum of its proper divisors (5518366548).

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

2561116500 is a wasteful number, since it uses less digits than its factorization.

2561116500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569162 (or 569147 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 2561116500 is about 50607.4747443498. The cubic root of 2561116500 is about 1368.1796022016.

The spelling of 2561116500 in words is "two billion, five hundred sixty-one million, one hundred sixteen thousand, five hundred".