1203813 has 12 divisors (see below), whose sum is σ = 1872780. Its totient is φ = 740736.

The previous prime is 1203809. The next prime is 1203817. The reversal of 1203813 is 3183021.

It is an interprime number because it is at equal distance from previous prime (1203809) and next prime (1203817).

It can be written as a sum of positive squares in 2 ways, for example, as 636804 + 567009 = 798^2 + 753^2 .

It is not a de Polignac number, because 1203813 - 2² = 1203809 is a prime.

1203813 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1203817) 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 in 11 ways as a sum of consecutive naturals, for example, 5028 + ... + 5261.

It is an arithmetic number, because the mean of its divisors is an integer number (156065).

2^1203813 is an apocalyptic number.

1203813 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1203813 is a deficient number, since it is larger than the sum of its proper divisors (668967).

1203813 is a wasteful number, since it uses less digits than its factorization.

1203813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10308 (or 10305 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1203813 is about 1097.1841231079. The cubic root of 1203813 is about 106.3782911691.

Adding to 1203813 its reverse (3183021), we get a palindrome (4386834).

It can be divided in two parts, 1203 and 813, that added together give a triangular number (2016 = T₆₃).

The spelling of 1203813 in words is "one million, two hundred three thousand, eight hundred thirteen".