1389221 has 2 divisors, whose sum is σ = 1389222. Its totient is φ = 1389220.

The previous prime is 1389217. The next prime is 1389229. The reversal of 1389221 is 1229831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1240996 + 148225 = 1114^2 + 385^2 .

It is a cyclic number.

It is not a de Polignac number, because 1389221 - 2² = 1389217 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1389229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 694610 + 694611.

It is an arithmetic number, because the mean of its divisors is an integer number (694611).

2^1389221 is an apocalyptic number.

It is an amenable number.

1389221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1389221 is an equidigital number, since it uses as much as digits as its factorization.

1389221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 26.

The square root of 1389221 is about 1178.6521963667. The cubic root of 1389221 is about 111.5810506831.

The spelling of 1389221 in words is "one million, three hundred eighty-nine thousand, two hundred twenty-one".