1813123431 has 72 divisors (see below), whose sum is σ = 3221215920. Its totient is φ = 977163264.

The previous prime is 1813123421. The next prime is 1813123441. The reversal of 1813123431 is 1343213181.

1813123431 is a `hidden beast` number, since 1 + 8 + 1 + 312 + 343 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (1813123421) and next prime (1813123441).

It is not a de Polignac number, because 1813123431 - 2⁷ = 1813123303 is a prime.

It is a super-2 number, since 2×1813123431² = 6574833152082423522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1813123395 and 1813123404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1813123421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2957481 + ... + 2958093.

It is an arithmetic number, because the mean of its divisors is an integer number (44739110).

Almost surely, 2^1813123431 is an apocalyptic number.

1813123431 is a deficient number, since it is larger than the sum of its proper divisors (1408092489).

1813123431 is a wasteful number, since it uses less digits than its factorization.

1813123431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1005 (or 995 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 1813123431 is about 42580.7871110904. The cubic root of 1813123431 is about 1219.3895160754.

The spelling of 1813123431 in words is "one billion, eight hundred thirteen million, one hundred twenty-three thousand, four hundred thirty-one".