16561056600 has 288 divisors, whose sum is σ = 64244035440. Its totient is φ = 3778560000.

The previous prime is 16561056581. The next prime is 16561056601. The reversal of 16561056600 is 665016561.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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 (16561056601) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 312000 + ... + 361200.

Almost surely, 2^16561056600 is an apocalyptic number.

16561056600 is a gapful number since it is divisible by the number (10) 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 16561056600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32122017720).

16561056600 is an abundant number, since it is smaller than the sum of its proper divisors (47682978840).

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

16561056600 is a wasteful number, since it uses less digits than its factorization.

16561056600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49251 (or 49239 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 16561056600 in words is "sixteen billion, five hundred sixty-one million, fifty-six thousand, six hundred".