18997733 has 2 divisors, whose sum is σ = 18997734. Its totient is φ = 18997732.

The previous prime is 18997723. The next prime is 18997757. The reversal of 18997733 is 33779981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17032129 + 1965604 = 4127^2 + 1402^2 .

It is a cyclic number.

It is not a de Polignac number, because 18997733 - 2⁴ = 18997717 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18997703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9498866 + 9498867.

It is an arithmetic number, because the mean of its divisors is an integer number (9498867).

Almost surely, 2^18997733 is an apocalyptic number.

It is an amenable number.

18997733 is a deficient number, since it is larger than the sum of its proper divisors (1).

18997733 is an equidigital number, since it uses as much as digits as its factorization.

18997733 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 18997733 is about 4358.6388930491. The cubic root of 18997733 is about 266.8295517018.

The spelling of 18997733 in words is "eighteen million, nine hundred ninety-seven thousand, seven hundred thirty-three".