1211813 has 2 divisors, whose sum is σ = 1211814. Its totient is φ = 1211812.

The previous prime is 1211807. The next prime is 1211827. The reversal of 1211813 is 3181121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1162084 + 49729 = 1078^2 + 223^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211813 - 2⁴ = 1211797 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1211791 and 1211800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605906 + 605907.

It is an arithmetic number, because the mean of its divisors is an integer number (605907).

2^1211813 is an apocalyptic number.

It is an amenable number.

1211813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211813 is an equidigital number, since it uses as much as digits as its factorization.

1211813 is an evil number, because the sum of its binary digits is even.

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

The square root of 1211813 is about 1100.8237824466. The cubic root of 1211813 is about 106.6134185184.

Adding to 1211813 its reverse (3181121), we get a palindrome (4392934).

The spelling of 1211813 in words is "one million, two hundred eleven thousand, eight hundred thirteen".