12811621 has 4 divisors (see below), whose sum is σ = 13368672. Its totient is φ = 12254572.

The previous prime is 12811607. The next prime is 12811661. The reversal of 12811621 is 12611821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12811621 - 2⁷ = 12811493 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12811592 and 12811601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12811661) 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, 278491 + ... + 278536.

It is an arithmetic number, because the mean of its divisors is an integer number (3342168).

Almost surely, 2^12811621 is an apocalyptic number.

It is an amenable number.

12811621 is a deficient number, since it is larger than the sum of its proper divisors (557051).

12811621 is an equidigital number, since it uses as much as digits as its factorization.

12811621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557050.

The product of its digits is 192, while the sum is 22.

The square root of 12811621 is about 3579.3324796671. The cubic root of 12811621 is about 233.9921893319.

The spelling of 12811621 in words is "twelve million, eight hundred eleven thousand, six hundred twenty-one".