1215871 has 4 divisors (see below), whose sum is σ = 1219552. Its totient is φ = 1212192.

The previous prime is 1215859. The next prime is 1215881. The reversal of 1215871 is 1785121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1215871 - 2⁵ = 1215839 is a prime.

It is an Ulam number.

It is a Duffinian number.

1215871 is a lucky number.

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1290 + ... + 2023.

It is an arithmetic number, because the mean of its divisors is an integer number (304888).

2^1215871 is an apocalyptic number.

1215871 is a deficient number, since it is larger than the sum of its proper divisors (3681).

1215871 is an equidigital number, since it uses as much as digits as its factorization.

1215871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3680.

The product of its digits is 560, while the sum is 25.

The square root of 1215871 is about 1102.6654070932. The cubic root of 1215871 is about 106.7322914315.

The spelling of 1215871 in words is "one million, two hundred fifteen thousand, eight hundred seventy-one".