1090021 has 2 divisors, whose sum is σ = 1090022. Its totient is φ = 1090020.

The previous prime is 1090013. The next prime is 1090027. The reversal of 1090021 is 1200901.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 829921 + 260100 = 911^2 + 510^2 .

It is a cyclic number.

It is not a de Polignac number, because 1090021 - 2³ = 1090013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1089983 and 1090010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1090027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545010 + 545011.

It is an arithmetic number, because the mean of its divisors is an integer number (545011).

2^1090021 is an apocalyptic number.

It is an amenable number.

1090021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1090021 is an equidigital number, since it uses as much as digits as its factorization.

1090021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 1090021 is about 1044.0407080186. The cubic root of 1090021 is about 102.9149075701.

Adding to 1090021 its reverse (1200901), we get a palindrome (2290922).

The spelling of 1090021 in words is "one million, ninety thousand, twenty-one".