7042421 has 2 divisors, whose sum is σ = 7042422. Its totient is φ = 7042420.

The previous prime is 7042391. The next prime is 7042423. The reversal of 7042421 is 1242407.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5808100 + 1234321 = 2410^2 + 1111^2 .

It is an emirp because it is prime and its reverse (1242407) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7042421 - 2²² = 2848117 is a prime.

It is a Sophie Germain prime.

Together with 7042423, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 7042393 and 7042402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7042423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3521210 + 3521211.

It is an arithmetic number, because the mean of its divisors is an integer number (3521211).

Almost surely, 2^7042421 is an apocalyptic number.

It is an amenable number.

7042421 is a deficient number, since it is larger than the sum of its proper divisors (1).

7042421 is an equidigital number, since it uses as much as digits as its factorization.

7042421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 7042421 is about 2653.7560174213. The cubic root of 7042421 is about 191.6787615136.

Adding to 7042421 its reverse (1242407), we get a palindrome (8284828).

It can be divided in two parts, 704 and 2421, that added together give a 5-th power (3125 = 5⁵).

The spelling of 7042421 in words is "seven million, forty-two thousand, four hundred twenty-one".