387221105 has 4 divisors (see below), whose sum is σ = 464665332. Its totient is φ = 309776880.

The previous prime is 387221101. The next prime is 387221143. The reversal of 387221105 is 501122783.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 274266721 + 112954384 = 16561^2 + 10628^2 .

It is not a de Polignac number, because 387221105 - 2² = 387221101 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (387221101) 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 in 3 ways as a sum of consecutive naturals, for example, 38722106 + ... + 38722115.

It is an arithmetic number, because the mean of its divisors is an integer number (116166333).

Almost surely, 2^387221105 is an apocalyptic number.

It is an amenable number.

387221105 is a deficient number, since it is larger than the sum of its proper divisors (77444227).

387221105 is an equidigital number, since it uses as much as digits as its factorization.

387221105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77444226.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 387221105 is about 19677.9344698573. The cubic root of 387221105 is about 728.8749198163.

Adding to 387221105 its reverse (501122783), we get a palindrome (888343888).

The spelling of 387221105 in words is "three hundred eighty-seven million, two hundred twenty-one thousand, one hundred five".