7839421 has 2 divisors, whose sum is σ = 7839422. Its totient is φ = 7839420.

The previous prime is 7839401. The next prime is 7839427. The reversal of 7839421 is 1249387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5244100 + 2595321 = 2290^2 + 1611^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7839421 is a prime.

It is a super-2 number, since 2×7839421² = 122913043230482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7839427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3919710 + 3919711.

It is an arithmetic number, because the mean of its divisors is an integer number (3919711).

Almost surely, 2^7839421 is an apocalyptic number.

It is an amenable number.

7839421 is a deficient number, since it is larger than the sum of its proper divisors (1).

7839421 is an equidigital number, since it uses as much as digits as its factorization.

7839421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 34.

The square root of 7839421 is about 2799.8966052338. The cubic root of 7839421 is about 198.6527871305.

Subtracting from 7839421 its sum of digits (34), we obtain a palindrome (7839387).

The spelling of 7839421 in words is "seven million, eight hundred thirty-nine thousand, four hundred twenty-one".