18667849 has 2 divisors, whose sum is σ = 18667850. Its totient is φ = 18667848.

The previous prime is 18667837. The next prime is 18667867. The reversal of 18667849 is 94876681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11269449 + 7398400 = 3357^2 + 2720^2 .

It is an emirp because it is prime and its reverse (94876681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18667849 - 2¹⁹ = 18143561 is a prime.

It is not a weakly prime, because it can be changed into another prime (18667829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9333924 + 9333925.

It is an arithmetic number, because the mean of its divisors is an integer number (9333925).

Almost surely, 2^18667849 is an apocalyptic number.

It is an amenable number.

18667849 is a deficient number, since it is larger than the sum of its proper divisors (1).

18667849 is an equidigital number, since it uses as much as digits as its factorization.

18667849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 580608, while the sum is 49.

The square root of 18667849 is about 4320.6306252676. The cubic root of 18667849 is about 265.2760810891.

The spelling of 18667849 in words is "eighteen million, six hundred sixty-seven thousand, eight hundred forty-nine".