18842437 has 2 divisors, whose sum is σ = 18842438. Its totient is φ = 18842436.

The previous prime is 18842413. The next prime is 18842491. The reversal of 18842437 is 73424881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18671041 + 171396 = 4321^2 + 414^2 .

It is an emirp because it is prime and its reverse (73424881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18842437 - 2⁷ = 18842309 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18842396 and 18842405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18842407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9421218 + 9421219.

It is an arithmetic number, because the mean of its divisors is an integer number (9421219).

Almost surely, 2^18842437 is an apocalyptic number.

It is an amenable number.

18842437 is a deficient number, since it is larger than the sum of its proper divisors (1).

18842437 is an equidigital number, since it uses as much as digits as its factorization.

18842437 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43008, while the sum is 37.

The square root of 18842437 is about 4340.7876013461. The cubic root of 18842437 is about 266.1005000235.

The spelling of 18842437 in words is "eighteen million, eight hundred forty-two thousand, four hundred thirty-seven".