2221381 has 2 divisors, whose sum is σ = 2221382. Its totient is φ = 2221380.

The previous prime is 2221379. The next prime is 2221391. The reversal of 2221381 is 1831222.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1288225 + 933156 = 1135^2 + 966^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221381 - 2¹ = 2221379 is a prime.

It is a super-2 number, since 2×2221381² = 9869067094322, which contains 22 as substring.

Together with 2221379, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2221301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1110690 + 1110691.

It is an arithmetic number, because the mean of its divisors is an integer number (1110691).

2^2221381 is an apocalyptic number.

2221381 is the 861-st hex number.

It is an amenable number.

2221381 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221381 is an equidigital number, since it uses as much as digits as its factorization.

2221381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 19.

The square root of 2221381 is about 1490.4298037814. The cubic root of 2221381 is about 130.4791195925.

The spelling of 2221381 in words is "two million, two hundred twenty-one thousand, three hundred eighty-one".