12105311621 has 8 divisors (see below), whose sum is σ = 13078143960. Its totient is φ = 11138429952.

The previous prime is 12105311611. The next prime is 12105311627. The reversal of 12105311621 is 12611350121.

It can be written as a sum of positive squares in 4 ways, for example, as 1845647521 + 10259664100 = 42961^2 + 101290^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12105311621 - 2²² = 12101117317 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 (12105311627) 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, 1483436 + ... + 1491573.

It is an arithmetic number, because the mean of its divisors is an integer number (1634767995).

Almost surely, 2^12105311621 is an apocalyptic number.

It is an amenable number.

12105311621 is a deficient number, since it is larger than the sum of its proper divisors (972832339).

12105311621 is a wasteful number, since it uses less digits than its factorization.

12105311621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2975335.

The product of its (nonzero) digits is 360, while the sum is 23.

Adding to 12105311621 its reverse (12611350121), we get a palindrome (24716661742).

The spelling of 12105311621 in words is "twelve billion, one hundred five million, three hundred eleven thousand, six hundred twenty-one".