11561806800 has 90 divisors (see below), whose sum is σ = 40122693702. Its totient is φ = 3083147520.

The previous prime is 11561806799. The next prime is 11561806801. The reversal of 11561806800 is 860816511.

11561806800 is a `hidden beast` number, since 11 + 561 + 8 + 0 + 6 + 80 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (11561806799) and next prime (11561806801).

It can be written as a sum of positive squares in 3 ways, for example, as 1729894464 + 9831912336 = 41592^2 + 99156^2 .

It is a tau number, because it is divible by the number of its divisors (90).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11561806801) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1602207 + ... + 1609406.

Almost surely, 2^11561806800 is an apocalyptic number.

11561806800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11561806800 is an abundant number, since it is smaller than the sum of its proper divisors (28560886902).

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

11561806800 is a wasteful number, since it uses less digits than its factorization.

11561806800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3211637 (or 3211623 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The spelling of 11561806800 in words is "eleven billion, five hundred sixty-one million, eight hundred six thousand, eight hundred".