12521612520 has 192 divisors, whose sum is σ = 42586099920. Its totient is φ = 3187372032.

The previous prime is 12521612501. The next prime is 12521612549. The reversal of 12521612520 is 2521612521.

12521612520 is a `hidden beast` number, since 1 + 2 + 5 + 21 + 612 + 5 + 20 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 11407521636 + 1114090884 = 106806^2 + 33378^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 697092 + ... + 714828.

Almost surely, 2^12521612520 is an apocalyptic number.

12521612520 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 12521612520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21293049960).

12521612520 is an abundant number, since it is smaller than the sum of its proper divisors (30064487400).

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

12521612520 is a wasteful number, since it uses less digits than its factorization.

12521612520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17844 (or 17837 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

Subtracting from 12521612520 its reverse (2521612521), we obtain a palindrome (9999999999).

The spelling of 12521612520 in words is "twelve billion, five hundred twenty-one million, six hundred twelve thousand, five hundred twenty".