12721511 has 4 divisors (see below), whose sum is σ = 13878024. Its totient is φ = 11565000.

The previous prime is 12721477. The next prime is 12721519. The reversal of 12721511 is 11512721.

It is a happy number.

12721511 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12721511 - 2⁶ = 12721447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12721519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 578240 + ... + 578261.

It is an arithmetic number, because the mean of its divisors is an integer number (3469506).

Almost surely, 2^12721511 is an apocalyptic number.

12721511 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12721511 is a deficient number, since it is larger than the sum of its proper divisors (1156513).

12721511 is a wasteful number, since it uses less digits than its factorization.

12721511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1156512.

The product of its digits is 140, while the sum is 20.

The square root of 12721511 is about 3566.7227254161. The cubic root of 12721511 is about 233.4423066948.

The spelling of 12721511 in words is "twelve million, seven hundred twenty-one thousand, five hundred eleven".