18344309 has 4 divisors (see below), whose sum is σ = 19423404. Its totient is φ = 17265216.

The previous prime is 18344303. The next prime is 18344311. The reversal of 18344309 is 90344381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90344381 = 277 ⋅326153.

It can be written as a sum of positive squares in 2 ways, for example, as 9284209 + 9060100 = 3047^2 + 3010^2 .

It is a cyclic number.

It is not a de Polignac number, because 18344309 - 2¹⁶ = 18278773 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 (18344303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 539522 + ... + 539555.

It is an arithmetic number, because the mean of its divisors is an integer number (4855851).

Almost surely, 2^18344309 is an apocalyptic number.

It is an amenable number.

18344309 is a deficient number, since it is larger than the sum of its proper divisors (1079095).

18344309 is a wasteful number, since it uses less digits than its factorization.

18344309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1079094.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 18344309 is about 4283.0256828555. The cubic root of 18344309 is about 263.7346056916.

The spelling of 18344309 in words is "eighteen million, three hundred forty-four thousand, three hundred nine".