1222420421 has 2 divisors, whose sum is σ = 1222420422. Its totient is φ = 1222420420.

The previous prime is 1222420417. The next prime is 1222420439. The reversal of 1222420421 is 1240242221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 649536196 + 572884225 = 25486^2 + 23935^2 .

It is a cyclic number.

It is not a de Polignac number, because 1222420421 - 2² = 1222420417 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1222420393 and 1222420402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1222420621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 611210210 + 611210211.

It is an arithmetic number, because the mean of its divisors is an integer number (611210211).

Almost surely, 2^1222420421 is an apocalyptic number.

It is an amenable number.

1222420421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1222420421 is an equidigital number, since it uses as much as digits as its factorization.

1222420421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 1222420421 is about 34963.1294508944. The cubic root of 1222420421 is about 1069.2359004553.

Adding to 1222420421 its reverse (1240242221), we get a palindrome (2462662642).

The spelling of 1222420421 in words is "one billion, two hundred twenty-two million, four hundred twenty thousand, four hundred twenty-one".