18399737 has 2 divisors, whose sum is σ = 18399738. Its totient is φ = 18399736.

The previous prime is 18399727. The next prime is 18399749. The reversal of 18399737 is 73799381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10214416 + 8185321 = 3196^2 + 2861^2 .

It is an emirp because it is prime and its reverse (73799381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18399737 - 2⁶ = 18399673 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18399691 and 18399700.

It is not a weakly prime, because it can be changed into another prime (18399727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9199868 + 9199869.

It is an arithmetic number, because the mean of its divisors is an integer number (9199869).

Almost surely, 2^18399737 is an apocalyptic number.

It is an amenable number.

18399737 is a deficient number, since it is larger than the sum of its proper divisors (1).

18399737 is an equidigital number, since it uses as much as digits as its factorization.

18399737 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 47.

The square root of 18399737 is about 4289.4914617003. The cubic root of 18399737 is about 263.9999665213. Note that the first 4 decimals are identical.

The spelling of 18399737 in words is "eighteen million, three hundred ninety-nine thousand, seven hundred thirty-seven".