1221428 has 24 divisors (see below), whose sum is σ = 2337888. Its totient is φ = 554976.

The previous prime is 1221427. The next prime is 1221443. The reversal of 1221428 is 8241221.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4175 + ... + 4457.

It is an arithmetic number, because the mean of its divisors is an integer number (97412).

2^1221428 is an apocalyptic number.

It is an amenable number.

1221428 is a deficient number, since it is larger than the sum of its proper divisors (1116460).

1221428 is a wasteful number, since it uses less digits than its factorization.

1221428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383 (or 381 counting only the distinct ones).

The product of its digits is 256, while the sum is 20.

The square root of 1221428 is about 1105.1823378972. The cubic root of 1221428 is about 106.8946469358.

Adding to 1221428 its reverse (8241221), we get a palindrome (9462649).

The spelling of 1221428 in words is "one million, two hundred twenty-one thousand, four hundred twenty-eight".