1212223421 has 2 divisors, whose sum is σ = 1212223422. Its totient is φ = 1212223420.

The previous prime is 1212223409. The next prime is 1212223423. The reversal of 1212223421 is 1243222121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1211388025 + 835396 = 34805^2 + 914^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212223421 - 2²⁶ = 1145114557 is a prime.

Together with 1212223423, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1212223393 and 1212223402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212223423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606111710 + 606111711.

It is an arithmetic number, because the mean of its divisors is an integer number (606111711).

Almost surely, 2^1212223421 is an apocalyptic number.

It is an amenable number.

1212223421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212223421 is an equidigital number, since it uses as much as digits as its factorization.

1212223421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 384, while the sum is 20.

The square root of 1212223421 is about 34816.9990234655. Note that the first 3 decimals coincide. The cubic root of 1212223421 is about 1066.2545322639.

Adding to 1212223421 its reverse (1243222121), we get a palindrome (2455445542).

The spelling of 1212223421 in words is "one billion, two hundred twelve million, two hundred twenty-three thousand, four hundred twenty-one".