12721691520 has 512 divisors, whose sum is σ = 46671120000. Its totient is φ = 3314442240.

The previous prime is 12721691503. The next prime is 12721691527. The reversal of 12721691520 is 2519612721.

12721691520 is a `hidden beast` number, since 1 + 2 + 72 + 1 + 69 + 1 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12721691527) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 85380406 + ... + 85380554.

Almost surely, 2^12721691520 is an apocalyptic number.

12721691520 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 12721691520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23335560000).

12721691520 is an abundant number, since it is smaller than the sum of its proper divisors (33949428480).

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

12721691520 is an frugal number, since it uses more digits than its factorization.

12721691520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 220 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The spelling of 12721691520 in words is "twelve billion, seven hundred twenty-one million, six hundred ninety-one thousand, five hundred twenty".