12721621 has 8 divisors (see below), whose sum is σ = 14608800. Its totient is φ = 10956240.

The previous prime is 12721609. The next prime is 12721651. The reversal of 12721621 is 12612721.

It is a happy number.

12721621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 12721621 - 2¹⁷ = 12590549 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12721592 and 12721601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12721601) 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, 30226 + ... + 30643.

It is an arithmetic number, because the mean of its divisors is an integer number (1826100).

Almost surely, 2^12721621 is an apocalyptic number.

12721621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12721621 is a deficient number, since it is larger than the sum of its proper divisors (1887179).

12721621 is a wasteful number, since it uses less digits than its factorization.

12721621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60899.

The product of its digits is 336, while the sum is 22.

The square root of 12721621 is about 3566.7381457012. The cubic root of 12721621 is about 233.4429795336.

Subtracting from 12721621 its reverse (12612721), we obtain a square (108900 = 330²).

The spelling of 12721621 in words is "twelve million, seven hundred twenty-one thousand, six hundred twenty-one".