3867221 has 2 divisors, whose sum is σ = 3867222. Its totient is φ = 3867220.

The previous prime is 3867209. The next prime is 3867223. The reversal of 3867221 is 1227683.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2292196 + 1575025 = 1514^2 + 1255^2 .

It is an emirp because it is prime and its reverse (1227683) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3867221 - 2¹⁴ = 3850837 is a prime.

Together with 3867223, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3867223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1933610 + 1933611.

It is an arithmetic number, because the mean of its divisors is an integer number (1933611).

Almost surely, 2^3867221 is an apocalyptic number.

It is an amenable number.

3867221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3867221 is an equidigital number, since it uses as much as digits as its factorization.

3867221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 29.

The square root of 3867221 is about 1966.5251078997. The cubic root of 3867221 is about 156.9638576926.

The spelling of 3867221 in words is "three million, eight hundred sixty-seven thousand, two hundred twenty-one".