395978521 has 2 divisors, whose sum is σ = 395978522. Its totient is φ = 395978520.

The previous prime is 395978497. The next prime is 395978537. The reversal of 395978521 is 125879593.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 389628121 + 6350400 = 19739^2 + 2520^2 .

It is a cyclic number.

It is not a de Polignac number, because 395978521 - 2⁷ = 395978393 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (395978591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197989260 + 197989261.

It is an arithmetic number, because the mean of its divisors is an integer number (197989261).

Almost surely, 2^395978521 is an apocalyptic number.

It is an amenable number.

395978521 is a deficient number, since it is larger than the sum of its proper divisors (1).

395978521 is an equidigital number, since it uses as much as digits as its factorization.

395978521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 680400, while the sum is 49.

The square root of 395978521 is about 19899.2090546333. The cubic root of 395978521 is about 734.3287690855.

The spelling of 395978521 in words is "three hundred ninety-five million, nine hundred seventy-eight thousand, five hundred twenty-one".