12721451 has 4 divisors (see below), whose sum is σ = 13065312. Its totient is φ = 12377592.

The previous prime is 12721447. The next prime is 12721477. The reversal of 12721451 is 15412721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15412721 = 151 ⋅102071.

It is a cyclic number.

It is not a de Polignac number, because 12721451 - 2² = 12721447 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12721411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171875 + ... + 171948.

It is an arithmetic number, because the mean of its divisors is an integer number (3266328).

Almost surely, 2^12721451 is an apocalyptic number.

12721451 is a deficient number, since it is larger than the sum of its proper divisors (343861).

12721451 is an equidigital number, since it uses as much as digits as its factorization.

12721451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343860.

The product of its digits is 560, while the sum is 23.

The square root of 12721451 is about 3566.7143143235. The cubic root of 12721451 is about 233.4419396901.

The spelling of 12721451 in words is "twelve million, seven hundred twenty-one thousand, four hundred fifty-one".