1021428 has 36 divisors (see below), whose sum is σ = 2735460. Its totient is φ = 320256.

The previous prime is 1021417. The next prime is 1021429. The reversal of 1021428 is 8241201.

It can be written as a sum of positive squares in 2 ways, for example, as 675684 + 345744 = 822^2 + 588^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 1021428.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021429) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 223 + ... + 1446.

It is an arithmetic number, because the mean of its divisors is an integer number (75985).

2^1021428 is an apocalyptic number.

1021428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1021428 is an abundant number, since it is smaller than the sum of its proper divisors (1714032).

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

1021428 is a wasteful number, since it uses less digits than its factorization.

1021428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1696 (or 1691 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 1021428 is about 1010.6572119171. The cubic root of 1021428 is about 100.7092247775.

Adding to 1021428 its reverse (8241201), we get a palindrome (9262629).

The spelling of 1021428 in words is "one million, twenty-one thousand, four hundred twenty-eight".