12667421 has 4 divisors (see below), whose sum is σ = 13641852. Its totient is φ = 11692992.

The previous prime is 12667387. The next prime is 12667427. The reversal of 12667421 is 12476621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12476621 = 283 ⋅44087.

It can be written as a sum of positive squares in 2 ways, for example, as 688900 + 11978521 = 830^2 + 3461^2 .

It is a cyclic number.

It is not a de Polignac number, because 12667421 - 2¹⁸ = 12405277 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 (12667427) 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, 487196 + ... + 487221.

It is an arithmetic number, because the mean of its divisors is an integer number (3410463).

Almost surely, 2^12667421 is an apocalyptic number.

It is an amenable number.

12667421 is a deficient number, since it is larger than the sum of its proper divisors (974431).

12667421 is an equidigital number, since it uses as much as digits as its factorization.

12667421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 974430.

The product of its digits is 4032, while the sum is 29.

The square root of 12667421 is about 3559.1320571173. The cubic root of 12667421 is about 233.1109825131.

The spelling of 12667421 in words is "twelve million, six hundred sixty-seven thousand, four hundred twenty-one".