7956821 has 2 divisors, whose sum is σ = 7956822. Its totient is φ = 7956820.

The previous prime is 7956803. The next prime is 7956847. The reversal of 7956821 is 1286597.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4056196 + 3900625 = 2014^2 + 1975^2 .

It is a cyclic number.

It is not a de Polignac number, because 7956821 - 2¹⁰ = 7955797 is a prime.

It is a super-2 number, since 2×7956821² = 126622000852082, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7956521) 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, 3978410 + 3978411.

It is an arithmetic number, because the mean of its divisors is an integer number (3978411).

Almost surely, 2^7956821 is an apocalyptic number.

It is an amenable number.

7956821 is a deficient number, since it is larger than the sum of its proper divisors (1).

7956821 is an equidigital number, since it uses as much as digits as its factorization.

7956821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 38.

The square root of 7956821 is about 2820.7837563344. The cubic root of 7956821 is about 199.6395256817.

The spelling of 7956821 in words is "seven million, nine hundred fifty-six thousand, eight hundred twenty-one".