12740721521 has 8 divisors (see below), whose sum is σ = 13904231904. Its totient is φ = 11578088320.

The previous prime is 12740721517. The next prime is 12740721551. The reversal of 12740721521 is 12512704721.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12740721521 - 2² = 12740721517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12740721551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188735 + ... + 247188.

It is an arithmetic number, because the mean of its divisors is an integer number (1738028988).

Almost surely, 2^12740721521 is an apocalyptic number.

12740721521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12740721521 is a deficient number, since it is larger than the sum of its proper divisors (1163510383).

12740721521 is a wasteful number, since it uses less digits than its factorization.

12740721521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438591.

The product of its (nonzero) digits is 7840, while the sum is 32.

The spelling of 12740721521 in words is "twelve billion, seven hundred forty million, seven hundred twenty-one thousand, five hundred twenty-one".