1225813 has 4 divisors (see below), whose sum is σ = 1231308. Its totient is φ = 1220320.

The previous prime is 1225787. The next prime is 1225817. The reversal of 1225813 is 3185221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 574564 + 651249 = 758^2 + 807^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1225813 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1225817) 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, 2398 + ... + 2863.

It is an arithmetic number, because the mean of its divisors is an integer number (307827).

2^1225813 is an apocalyptic number.

It is an amenable number.

1225813 is a deficient number, since it is larger than the sum of its proper divisors (5495).

1225813 is an equidigital number, since it uses as much as digits as its factorization.

1225813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5494.

The product of its digits is 480, while the sum is 22.

The square root of 1225813 is about 1107.1643961038. The cubic root of 1225813 is about 107.0224135653.

The spelling of 1225813 in words is "one million, two hundred twenty-five thousand, eight hundred thirteen".