18487939 has 2 divisors, whose sum is σ = 18487940. Its totient is φ = 18487938.

The previous prime is 18487933. The next prime is 18487943. The reversal of 18487939 is 93978481.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (93978481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18487939 - 2¹¹ = 18485891 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18487892 and 18487901.

It is not a weakly prime, because it can be changed into another prime (18487933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9243969 + 9243970.

It is an arithmetic number, because the mean of its divisors is an integer number (9243970).

Almost surely, 2^18487939 is an apocalyptic number.

18487939 is a deficient number, since it is larger than the sum of its proper divisors (1).

18487939 is an equidigital number, since it uses as much as digits as its factorization.

18487939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 49.

The square root of 18487939 is about 4299.7603421586. The cubic root of 18487939 is about 264.4211358844.

The spelling of 18487939 in words is "eighteen million, four hundred eighty-seven thousand, nine hundred thirty-nine".