12521109426 has 96 divisors (see below), whose sum is σ = 30951365760. Its totient is φ = 3303750912.

The previous prime is 12521109371. The next prime is 12521109427. The reversal of 12521109426 is 62490112521.

It is not an unprimeable number, because it can be changed into a prime (12521109427) 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 47 ways as a sum of consecutive naturals, for example, 634606 + ... + 654038.

It is an arithmetic number, because the mean of its divisors is an integer number (322410060).

Almost surely, 2^12521109426 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12521109426, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15475682880).

12521109426 is an abundant number, since it is smaller than the sum of its proper divisors (18430256334).

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

12521109426 is a wasteful number, since it uses less digits than its factorization.

12521109426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19520 (or 19497 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The spelling of 12521109426 in words is "twelve billion, five hundred twenty-one million, one hundred nine thousand, four hundred twenty-six".