18947449 has 2 divisors, whose sum is σ = 18947450. Its totient is φ = 18947448.

The previous prime is 18947429. The next prime is 18947459. The reversal of 18947449 is 94474981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14402025 + 4545424 = 3795^2 + 2132^2 .

It is a cyclic number.

It is not a de Polignac number, because 18947449 - 2⁷ = 18947321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18947399 and 18947408.

It is not a weakly prime, because it can be changed into another prime (18947419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9473724 + 9473725.

It is an arithmetic number, because the mean of its divisors is an integer number (9473725).

Almost surely, 2^18947449 is an apocalyptic number.

It is an amenable number.

18947449 is a deficient number, since it is larger than the sum of its proper divisors (1).

18947449 is an equidigital number, since it uses as much as digits as its factorization.

18947449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 46.

The square root of 18947449 is about 4352.8667565181. The cubic root of 18947449 is about 266.5939251246.

The spelling of 18947449 in words is "eighteen million, nine hundred forty-seven thousand, four hundred forty-nine".