1220443421 has 2 divisors, whose sum is σ = 1220443422. Its totient is φ = 1220443420.

The previous prime is 1220443417. The next prime is 1220443423. The reversal of 1220443421 is 1243440221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1207562500 + 12880921 = 34750^2 + 3589^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220443421 - 2² = 1220443417 is a prime.

Together with 1220443423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220443423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610221710 + 610221711.

It is an arithmetic number, because the mean of its divisors is an integer number (610221711).

Almost surely, 2^1220443421 is an apocalyptic number.

It is an amenable number.

1220443421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220443421 is an equidigital number, since it uses as much as digits as its factorization.

1220443421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 23.

The square root of 1220443421 is about 34934.8453696306. The cubic root of 1220443421 is about 1068.6591703482.

Adding to 1220443421 its reverse (1243440221), we get a palindrome (2463883642).

The spelling of 1220443421 in words is "one billion, two hundred twenty million, four hundred forty-three thousand, four hundred twenty-one".