1028220 has 24 divisors (see below), whose sum is σ = 2879184. Its totient is φ = 274176.

The previous prime is 1028213. The next prime is 1028221. The reversal of 1028220 is 228201.

1028220 = 355² + 356² + ... + 362².

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1028220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1028221) 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, 8509 + ... + 8628.

It is an arithmetic number, because the mean of its divisors is an integer number (119966).

2^1028220 is an apocalyptic number.

1028220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1028220 is an abundant number, since it is smaller than the sum of its proper divisors (1850964).

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

1028220 is a wasteful number, since it uses less digits than its factorization.

1028220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17149 (or 17147 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 1028220 is about 1014.0118342505. The cubic root of 1028220 is about 100.9319542973.

The spelling of 1028220 in words is "one million, twenty-eight thousand, two hundred twenty".