12126090661 has 4 divisors (see below), whose sum is σ = 12127279500. Its totient is φ = 12124901824.

The previous prime is 12126090619. The next prime is 12126090733. The reversal of 12126090661 is 16609062121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16609062121 = 12541 ⋅1324381.

It can be written as a sum of positive squares in 2 ways, for example, as 9441814561 + 2684276100 = 97169^2 + 51810^2 .

It is a cyclic number.

It is not a de Polignac number, because 12126090661 - 2¹¹ = 12126088613 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 (12126090461) 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, 578986 + ... + 599563.

It is an arithmetic number, because the mean of its divisors is an integer number (3031819875).

Almost surely, 2^12126090661 is an apocalyptic number.

It is an amenable number.

12126090661 is a deficient number, since it is larger than the sum of its proper divisors (1188839).

12126090661 is a wasteful number, since it uses less digits than its factorization.

12126090661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1188838.

The product of its (nonzero) digits is 7776, while the sum is 34.

The spelling of 12126090661 in words is "twelve billion, one hundred twenty-six million, ninety thousand, six hundred sixty-one".