1215889 has 4 divisors (see below), whose sum is σ = 1231360. Its totient is φ = 1200420.

The previous prime is 1215881. The next prime is 1215899. The reversal of 1215889 is 9885121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9885121 = 409 ⋅24169.

It is a cyclic number.

It is not a de Polignac number, because 1215889 - 2³ = 1215881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1215881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7617 + ... + 7774.

It is an arithmetic number, because the mean of its divisors is an integer number (307840).

2^1215889 is an apocalyptic number.

It is an amenable number.

1215889 is a deficient number, since it is larger than the sum of its proper divisors (15471).

1215889 is an equidigital number, since it uses as much as digits as its factorization.

1215889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15470.

The product of its digits is 5760, while the sum is 34.

The square root of 1215889 is about 1102.6735691037. The cubic root of 1215889 is about 106.7328181244.

The spelling of 1215889 in words is "one million, two hundred fifteen thousand, eight hundred eighty-nine".