12123561546 has 64 divisors (see below), whose sum is σ = 27981158400. Its totient is φ = 3888119088.

The previous prime is 12123561511. The next prime is 12123561547. The reversal of 12123561546 is 64516532121.

12123561546 is a `hidden beast` number, since 1 + 2 + 1 + 2 + 35 + 615 + 4 + 6 = 666.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12123561546.

It is not an unprimeable number, because it can be changed into a prime (12123561547) 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 31 ways as a sum of consecutive naturals, for example, 109261 + ... + 190223.

It is an arithmetic number, because the mean of its divisors is an integer number (437205600).

Almost surely, 2^12123561546 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12123561546, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13990579200).

12123561546 is an abundant number, since it is smaller than the sum of its proper divisors (15857596854).

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

12123561546 is a wasteful number, since it uses less digits than its factorization.

12123561546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81080 (or 81074 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The spelling of 12123561546 in words is "twelve billion, one hundred twenty-three million, five hundred sixty-one thousand, five hundred forty-six".