1428821 has 4 divisors (see below), whose sum is σ = 1474944. Its totient is φ = 1382700.

The previous prime is 1428811. The next prime is 1428839. The reversal of 1428821 is 1288241.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1288241 = 269 ⋅4789.

It is a cyclic number.

It is not a de Polignac number, because 1428821 - 2¹⁸ = 1166677 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1428811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23015 + ... + 23076.

It is an arithmetic number, because the mean of its divisors is an integer number (368736).

2^1428821 is an apocalyptic number.

It is an amenable number.

1428821 is a deficient number, since it is larger than the sum of its proper divisors (46123).

1428821 is an equidigital number, since it uses as much as digits as its factorization.

1428821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46122.

The product of its digits is 1024, while the sum is 26.

The square root of 1428821 is about 1195.3330079940. Note that the first 3 decimals coincide. The cubic root of 1428821 is about 112.6313461793.

The spelling of 1428821 in words is "one million, four hundred twenty-eight thousand, eight hundred twenty-one".