1815013813 has 2 divisors, whose sum is σ = 1815013814. Its totient is φ = 1815013812.

The previous prime is 1815013801. The next prime is 1815013841. The reversal of 1815013813 is 3183105181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1803021444 + 11992369 = 42462^2 + 3463^2 .

It is a cyclic number.

It is not a de Polignac number, because 1815013813 - 2⁹ = 1815013301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1815013843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 907506906 + 907506907.

It is an arithmetic number, because the mean of its divisors is an integer number (907506907).

Almost surely, 2^1815013813 is an apocalyptic number.

It is an amenable number.

1815013813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1815013813 is an equidigital number, since it uses as much as digits as its factorization.

1815013813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 1815013813 is about 42602.9789216670. The cubic root of 1815013813 is about 1219.8131517575.

Adding to 1815013813 its reverse (3183105181), we get a palindrome (4998118994).

The spelling of 1815013813 in words is "one billion, eight hundred fifteen million, thirteen thousand, eight hundred thirteen".