12721305520 has 480 divisors, whose sum is σ = 39864877056. Its totient is φ = 3725568000.

The previous prime is 12721305469. The next prime is 12721305557. The reversal of 12721305520 is 2550312721.

It is a super-2 number, since 2×12721305520² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 100167697 + ... + 100167823.

Almost surely, 2^12721305520 is an apocalyptic number.

12721305520 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 12721305520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19932438528).

12721305520 is an abundant number, since it is smaller than the sum of its proper divisors (27143571536).

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

12721305520 is a wasteful number, since it uses less digits than its factorization.

12721305520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289 (or 276 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 28.

The spelling of 12721305520 in words is "twelve billion, seven hundred twenty-one million, three hundred five thousand, five hundred twenty".