1217391 has 16 divisors (see below), whose sum is σ = 1920000. Its totient is φ = 671328.

The previous prime is 1217351. The next prime is 1217393. The reversal of 1217391 is 1937121.

It is not a de Polignac number, because 1217391 - 2⁹ = 1216879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 391 + ... + 1608.

It is an arithmetic number, because the mean of its divisors is an integer number (120000).

2^1217391 is an apocalyptic number.

1217391 is a deficient number, since it is larger than the sum of its proper divisors (702609).

1217391 is a wasteful number, since it uses less digits than its factorization.

1217391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2038.

The product of its digits is 378, while the sum is 24.

The square root of 1217391 is about 1103.3544308154. The cubic root of 1217391 is about 106.7767494169.

The spelling of 1217391 in words is "one million, two hundred seventeen thousand, three hundred ninety-one".