1938182221 has 2 divisors, whose sum is σ = 1938182222. Its totient is φ = 1938182220.

The previous prime is 1938182203. The next prime is 1938182249. The reversal of 1938182221 is 1222818391.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1309426596 + 628755625 = 36186^2 + 25075^2 .

It is a cyclic number.

It is not a de Polignac number, because 1938182221 - 2⁹ = 1938181709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1938182261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 969091110 + 969091111.

It is an arithmetic number, because the mean of its divisors is an integer number (969091111).

Almost surely, 2^1938182221 is an apocalyptic number.

It is an amenable number.

1938182221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1938182221 is an equidigital number, since it uses as much as digits as its factorization.

1938182221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 37.

The square root of 1938182221 is about 44024.7909819002. The cubic root of 1938182221 is about 1246.8040427968.

The spelling of 1938182221 in words is "one billion, nine hundred thirty-eight million, one hundred eighty-two thousand, two hundred twenty-one".