12721505 has 4 divisors (see below), whose sum is σ = 15265812. Its totient is φ = 10177200.

The previous prime is 12721477. The next prime is 12721519. The reversal of 12721505 is 50512721.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6806881 + 5914624 = 2609^2 + 2432^2 .

It is not a de Polignac number, because 12721505 - 2⁶ = 12721441 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1272146 + ... + 1272155.

It is an arithmetic number, because the mean of its divisors is an integer number (3816453).

Almost surely, 2^12721505 is an apocalyptic number.

It is an amenable number.

12721505 is a deficient number, since it is larger than the sum of its proper divisors (2544307).

12721505 is an equidigital number, since it uses as much as digits as its factorization.

12721505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2544306.

The product of its (nonzero) digits is 700, while the sum is 23.

The square root of 12721505 is about 3566.7218843078. The cubic root of 12721505 is about 233.4422699944.

The spelling of 12721505 in words is "twelve million, seven hundred twenty-one thousand, five hundred five".