1021221 has 16 divisors (see below), whose sum is σ = 1531200. Its totient is φ = 672624.

The previous prime is 1021217. The next prime is 1021243. The reversal of 1021221 is 1221201.

It is not a de Polignac number, because 1021221 - 2² = 1021217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2770 + ... + 3116.

It is an arithmetic number, because the mean of its divisors is an integer number (95700).

2^1021221 is an apocalyptic number.

It is an amenable number.

1021221 is a deficient number, since it is larger than the sum of its proper divisors (509979).

1021221 is a wasteful number, since it uses less digits than its factorization.

1021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465 (or 459 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1021221 is about 1010.5547981183. The cubic root of 1021221 is about 100.7024211594.

Adding to 1021221 its reverse (1221201), we get a palindrome (2242422).

The spelling of 1021221 in words is "one million, twenty-one thousand, two hundred twenty-one".