1221420424 has 16 divisors (see below), whose sum is σ = 2617329600. Its totient is φ = 523465872.

The previous prime is 1221420397. The next prime is 1221420449. The reversal of 1221420424 is 4240241221.

It is a junction number, because it is equal to n+sod(n) for n = 1221420395 and 1221420404.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10905484 + ... + 10905595.

It is an arithmetic number, because the mean of its divisors is an integer number (163583100).

Almost surely, 2^1221420424 is an apocalyptic number.

1221420424 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1221420424 is an abundant number, since it is smaller than the sum of its proper divisors (1395909176).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221420424 is a wasteful number, since it uses less digits than its factorization.

1221420424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21811092 (or 21811088 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 22.

The square root of 1221420424 is about 34948.8257885726. The cubic root of 1221420424 is about 1068.9442592796.

Adding to 1221420424 its reverse (4240241221), we get a palindrome (5461661645).

The spelling of 1221420424 in words is "one billion, two hundred twenty-one million, four hundred twenty thousand, four hundred twenty-four".