3138221 has 2 divisors, whose sum is σ = 3138222. Its totient is φ = 3138220.

The previous prime is 3138209. The next prime is 3138283. The reversal of 3138221 is 1228313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2592100 + 546121 = 1610^2 + 739^2 .

It is a cyclic number.

It is not a de Polignac number, because 3138221 - 2¹⁴ = 3121837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 3138193 and 3138202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3138521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1569110 + 1569111.

It is an arithmetic number, because the mean of its divisors is an integer number (1569111).

Almost surely, 2^3138221 is an apocalyptic number.

It is an amenable number.

3138221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3138221 is an equidigital number, since it uses as much as digits as its factorization.

3138221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288, while the sum is 20.

The square root of 3138221 is about 1771.5024696568. The cubic root of 3138221 is about 146.4067751699.

The spelling of 3138221 in words is "three million, one hundred thirty-eight thousand, two hundred twenty-one".