19897733 has 2 divisors, whose sum is σ = 19897734. Its totient is φ = 19897732.

The previous prime is 19897729. The next prime is 19897747. The reversal of 19897733 is 33779891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17581249 + 2316484 = 4193^2 + 1522^2 .

It is a cyclic number.

It is not a de Polignac number, because 19897733 - 2² = 19897729 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19897763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9948866 + 9948867.

It is an arithmetic number, because the mean of its divisors is an integer number (9948867).

Almost surely, 2^19897733 is an apocalyptic number.

It is an amenable number.

19897733 is a deficient number, since it is larger than the sum of its proper divisors (1).

19897733 is an equidigital number, since it uses as much as digits as its factorization.

19897733 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 19897733 is about 4460.6875030650. The cubic root of 19897733 is about 270.9783119220.

The spelling of 19897733 in words is "nineteen million, eight hundred ninety-seven thousand, seven hundred thirty-three".