18344813 has 2 divisors, whose sum is σ = 18344814. Its totient is φ = 18344812.

The previous prime is 18344773. The next prime is 18344831. The reversal of 18344813 is 31844381.

Together with next prime (18344831) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10125124 + 8219689 = 3182^2 + 2867^2 .

It is a cyclic number.

It is not a de Polignac number, because 18344813 - 2⁶ = 18344749 is a prime.

It is equal to p_1171967 and since 18344813 and 1171967 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18344813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18344863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9172406 + 9172407.

It is an arithmetic number, because the mean of its divisors is an integer number (9172407).

Almost surely, 2^18344813 is an apocalyptic number.

It is an amenable number.

18344813 is a deficient number, since it is larger than the sum of its proper divisors (1).

18344813 is an equidigital number, since it uses as much as digits as its factorization.

18344813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9216, while the sum is 32.

The square root of 18344813 is about 4283.0845193622. The cubic root of 18344813 is about 263.7370209916.

The spelling of 18344813 in words is "eighteen million, three hundred forty-four thousand, eight hundred thirteen".