1222420021 has 4 divisors (see below), whose sum is σ = 1226350944. Its totient is φ = 1218489100.

The previous prime is 1222420013. The next prime is 1222420033. The reversal of 1222420021 is 1200242221.

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.

It is a cyclic number.

It is not a de Polignac number, because 1222420021 - 2³ = 1222420013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1222419977 and 1222420004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1222420061) 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, 1964995 + ... + 1965616.

It is an arithmetic number, because the mean of its divisors is an integer number (306587736).

Almost surely, 2^1222420021 is an apocalyptic number.

It is an amenable number.

1222420021 is a deficient number, since it is larger than the sum of its proper divisors (3930923).

1222420021 is an equidigital number, since it uses as much as digits as its factorization.

1222420021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3930922.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 1222420021 is about 34963.1237305822. The cubic root of 1222420021 is about 1069.2357838302.

Adding to 1222420021 its reverse (1200242221), we get a palindrome (2422662242).

The spelling of 1222420021 in words is "one billion, two hundred twenty-two million, four hundred twenty thousand, twenty-one".