12421000021 has 4 divisors (see below), whose sum is σ = 12443062752. Its totient is φ = 12398937292.

The previous prime is 12421000019. The next prime is 12421000027. The reversal of 12421000021 is 12000012421.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12000012421 = 67 ⋅179104663.

It is a cyclic number.

It is not a de Polignac number, because 12421000021 - 2¹ = 12421000019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12420999965 and 12421000010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12421000027) 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, 11030521 + ... + 11031646.

It is an arithmetic number, because the mean of its divisors is an integer number (3110765688).

Almost surely, 2^12421000021 is an apocalyptic number.

It is an amenable number.

12421000021 is a deficient number, since it is larger than the sum of its proper divisors (22062731).

12421000021 is an equidigital number, since it uses as much as digits as its factorization.

12421000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22062730.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 12421000021 its reverse (12000012421), we get a palindrome (24421012442).

The spelling of 12421000021 in words is "twelve billion, four hundred twenty-one million, twenty-one", and thus it is an aban number.