381550221 has 12 divisors (see below), whose sum is σ = 593522748. Its totient is φ = 234800064.

The previous prime is 381550219. The next prime is 381550271. The reversal of 381550221 is 122055183.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 93026025 + 288524196 = 9645^2 + 16986^2 .

It is not a de Polignac number, because 381550221 - 2¹ = 381550219 is a prime.

It is a super-2 number, since 2×381550221² = 291161142290297682, which contains 22 as substring.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381550271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1630440 + ... + 1630673.

It is an arithmetic number, because the mean of its divisors is an integer number (49460229).

Almost surely, 2^381550221 is an apocalyptic number.

It is an amenable number.

381550221 is a deficient number, since it is larger than the sum of its proper divisors (211972527).

381550221 is a wasteful number, since it uses less digits than its factorization.

381550221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3261132 (or 3261129 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 381550221 is about 19533.3105489059. The cubic root of 381550221 is about 725.2992635327.

The spelling of 381550221 in words is "three hundred eighty-one million, five hundred fifty thousand, two hundred twenty-one".