1026821 has 4 divisors (see below), whose sum is σ = 1029600. Its totient is φ = 1024044.

The previous prime is 1026811. The next prime is 1026829. The reversal of 1026821 is 1286201.

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.

It is a cyclic number.

It is not a de Polignac number, because 1026821 - 2⁶ = 1026757 is a prime.

It is a super-2 number, since 2×1026821² = 2108722732082, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1026793 and 1026802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1026829) 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 3 ways as a sum of consecutive naturals, for example, 731 + ... + 1608.

It is an arithmetic number, because the mean of its divisors is an integer number (257400).

2^1026821 is an apocalyptic number.

It is an amenable number.

1026821 is a deficient number, since it is larger than the sum of its proper divisors (2779).

1026821 is an equidigital number, since it uses as much as digits as its factorization.

1026821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2778.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 1026821 is about 1013.3217652848. The cubic root of 1026821 is about 100.8861573883.

The spelling of 1026821 in words is "one million, twenty-six thousand, eight hundred twenty-one".