7543021 has 2 divisors, whose sum is σ = 7543022. Its totient is φ = 7543020.

The previous prime is 7543009. The next prime is 7543043. The reversal of 7543021 is 1203457.

It is an a-pointer prime, because the next prime (7543043) can be obtained adding 7543021 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6687396 + 855625 = 2586^2 + 925^2 .

It is an emirp because it is prime and its reverse (1203457) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7543021 - 2⁵ = 7542989 is a prime.

It is a Chen prime.

7543021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 7542983 and 7543001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7543001) 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 as a sum of consecutive naturals, namely, 3771510 + 3771511.

It is an arithmetic number, because the mean of its divisors is an integer number (3771511).

Almost surely, 2^7543021 is an apocalyptic number.

It is an amenable number.

7543021 is a deficient number, since it is larger than the sum of its proper divisors (1).

7543021 is an equidigital number, since it uses as much as digits as its factorization.

7543021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 7543021 is about 2746.4560801149. The cubic root of 7543021 is about 196.1169387555.

Adding to 7543021 its reverse (1203457), we get a palindrome (8746478).

The spelling of 7543021 in words is "seven million, five hundred forty-three thousand, twenty-one".