1813121 has 2 divisors, whose sum is σ = 1813122. Its totient is φ = 1813120.

The previous prime is 1813081. The next prime is 1813139. The reversal of 1813121 is 1213181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1809025 + 4096 = 1345^2 + 64^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1813121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1813121.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1813321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 906560 + 906561.

It is an arithmetic number, because the mean of its divisors is an integer number (906561).

2^1813121 is an apocalyptic number.

It is an amenable number.

1813121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1813121 is an equidigital number, since it uses as much as digits as its factorization.

1813121 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 1813121 is about 1346.5218156421. The cubic root of 1813121 is about 121.9388971097.

The spelling of 1813121 in words is "one million, eight hundred thirteen thousand, one hundred twenty-one".