1213918 has 4 divisors (see below), whose sum is σ = 1820880. Its totient is φ = 606958.

The previous prime is 1213913. The next prime is 1213921. The reversal of 1213918 is 8193121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8193121 = 1669 ⋅4909.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 1213892 and 1213901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213913) 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 as a sum of consecutive naturals, namely, 303478 + ... + 303481.

It is an arithmetic number, because the mean of its divisors is an integer number (455220).

2^1213918 is an apocalyptic number.

1213918 is a deficient number, since it is larger than the sum of its proper divisors (606962).

1213918 is an equidigital number, since it uses as much as digits as its factorization.

1213918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606961.

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

The square root of 1213918 is about 1101.7794697670. The cubic root of 1213918 is about 106.6751143483.

The spelling of 1213918 in words is "one million, two hundred thirteen thousand, nine hundred eighteen".