387819221 has 2 divisors, whose sum is σ = 387819222. Its totient is φ = 387819220.

The previous prime is 387819209. The next prime is 387819227. The reversal of 387819221 is 122918783.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 356794321 + 31024900 = 18889^2 + 5570^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-387819221 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (387819227) 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, 193909610 + 193909611.

It is an arithmetic number, because the mean of its divisors is an integer number (193909611).

Almost surely, 2^387819221 is an apocalyptic number.

It is an amenable number.

387819221 is a deficient number, since it is larger than the sum of its proper divisors (1).

387819221 is an equidigital number, since it uses as much as digits as its factorization.

387819221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 41.

The square root of 387819221 is about 19693.1262373448. The cubic root of 387819221 is about 729.2500091179.

The spelling of 387819221 in words is "three hundred eighty-seven million, eight hundred nineteen thousand, two hundred twenty-one".