1213391 has 4 divisors (see below), whose sum is σ = 1219872. Its totient is φ = 1206912.

The previous prime is 1213379. The next prime is 1213427. The reversal of 1213391 is 1933121.

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 1213391 - 2⁶ = 1213327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2951 + ... + 3336.

It is an arithmetic number, because the mean of its divisors is an integer number (304968).

2^1213391 is an apocalyptic number.

1213391 is a deficient number, since it is larger than the sum of its proper divisors (6481).

1213391 is an equidigital number, since it uses as much as digits as its factorization.

1213391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6480.

The product of its digits is 162, while the sum is 20.

The square root of 1213391 is about 1101.5402852370. The cubic root of 1213391 is about 106.6596751060.

The spelling of 1213391 in words is "one million, two hundred thirteen thousand, three hundred ninety-one".