1213811 has 4 divisors (see below), whose sum is σ = 1218792. Its totient is φ = 1208832.

The previous prime is 1213801. The next prime is 1213829. The reversal of 1213811 is 1183121.

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 1213811 - 2⁶ = 1213747 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1213811.

It is not an unprimeable number, because it can be changed into a prime (1213801) 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, 2105 + ... + 2618.

It is an arithmetic number, because the mean of its divisors is an integer number (304698).

2^1213811 is an apocalyptic number.

1213811 is a deficient number, since it is larger than the sum of its proper divisors (4981).

1213811 is an equidigital number, since it uses as much as digits as its factorization.

1213811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4980.

The product of its digits is 48, while the sum is 17.

The square root of 1213811 is about 1101.7309108852. The cubic root of 1213811 is about 106.6719799871.

Adding to 1213811 its reverse (1183121), we get a palindrome (2396932).

The spelling of 1213811 in words is "one million, two hundred thirteen thousand, eight hundred eleven".