1231813 has 8 divisors (see below), whose sum is σ = 1357056. Its totient is φ = 1108800.

The previous prime is 1231807. The next prime is 1231817. The reversal of 1231813 is 3181321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1231813 - 2⁵ = 1231781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231817) 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 7 ways as a sum of consecutive naturals, for example, 748 + ... + 1738.

It is an arithmetic number, because the mean of its divisors is an integer number (169632).

2^1231813 is an apocalyptic number.

It is an amenable number.

1231813 is a deficient number, since it is larger than the sum of its proper divisors (125243).

1231813 is a wasteful number, since it uses less digits than its factorization.

1231813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1115.

The product of its digits is 144, while the sum is 19.

The square root of 1231813 is about 1109.8707131914. The cubic root of 1231813 is about 107.1967440256.

It can be divided in two parts, 123 and 1813, that added together give a square (1936 = 44²).

The spelling of 1231813 in words is "one million, two hundred thirty-one thousand, eight hundred thirteen".