1243021 has 4 divisors (see below), whose sum is σ = 1338652. Its totient is φ = 1147392.

The previous prime is 1243013. The next prime is 1243093. The reversal of 1243021 is 1203421.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 220900 + 1022121 = 470^2 + 1011^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243021 - 2³ = 1243013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 95617 = 1243021 / (1 + 2 + 4 + 3 + 0 + 2 + 1).

It is a Duffinian number.

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 1242992 and 1243010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243421) 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 3 ways as a sum of consecutive naturals, for example, 47796 + ... + 47821.

It is an arithmetic number, because the mean of its divisors is an integer number (334663).

2^1243021 is an apocalyptic number.

It is an amenable number.

1243021 is a deficient number, since it is larger than the sum of its proper divisors (95631).

1243021 is an equidigital number, since it uses as much as digits as its factorization.

1243021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95630.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 1243021 is about 1114.9085164263. The cubic root of 1243021 is about 107.5208829090.

Adding to 1243021 its reverse (1203421), we get a palindrome (2446442).

The spelling of 1243021 in words is "one million, two hundred forty-three thousand, twenty-one".