16561654550 has 72 divisors (see below), whose sum is σ = 35893155816. Its totient is φ = 5668911360.

The previous prime is 16561654537. The next prime is 16561654559. The reversal of 16561654550 is 5545616561.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561654559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1570094 + ... + 1580606.

It is an arithmetic number, because the mean of its divisors is an integer number (498516053).

Almost surely, 2^16561654550 is an apocalyptic number.

16561654550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16561654550 is an abundant number, since it is smaller than the sum of its proper divisors (19331501266).

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

16561654550 is a wasteful number, since it uses less digits than its factorization.

16561654550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11182 (or 11170 counting only the distinct ones).

The product of its (nonzero) digits is 540000, while the sum is 44.

The spelling of 16561654550 in words is "sixteen billion, five hundred sixty-one million, six hundred fifty-four thousand, five hundred fifty".