1211389 has 2 divisors, whose sum is σ = 1211390. Its totient is φ = 1211388.

The previous prime is 1211381. The next prime is 1211393. The reversal of 1211389 is 9831121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1138489 + 72900 = 1067^2 + 270^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211389 - 2³ = 1211381 is a prime.

It is a super-3 number, since 3×1211389³ = 5333006732445170607, which contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211381) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605694 + 605695.

It is an arithmetic number, because the mean of its divisors is an integer number (605695).

2^1211389 is an apocalyptic number.

It is an amenable number.

1211389 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211389 is an equidigital number, since it uses as much as digits as its factorization.

1211389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 25.

The square root of 1211389 is about 1100.6311825494. The cubic root of 1211389 is about 106.6009827815.

It can be divided in two parts, 1211 and 389, that added together give a square (1600 = 40²).

The spelling of 1211389 in words is "one million, two hundred eleven thousand, three hundred eighty-nine".