19764449 has 2 divisors, whose sum is σ = 19764450. Its totient is φ = 19764448.

The previous prime is 19764443. The next prime is 19764461. The reversal of 19764449 is 94446791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14326225 + 5438224 = 3785^2 + 2332^2 .

It is a cyclic number.

It is not a de Polignac number, because 19764449 - 2⁸ = 19764193 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (19764443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9882224 + 9882225.

It is an arithmetic number, because the mean of its divisors is an integer number (9882225).

Almost surely, 2^19764449 is an apocalyptic number.

It is an amenable number.

19764449 is a deficient number, since it is larger than the sum of its proper divisors (1).

19764449 is an equidigital number, since it uses as much as digits as its factorization.

19764449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 44.

The square root of 19764449 is about 4445.7225509471. The cubic root of 19764449 is about 270.3719108880.

It can be divided in two parts, 197 and 64449, that added together give a palindrome (64646).

The spelling of 19764449 in words is "nineteen million, seven hundred sixty-four thousand, four hundred forty-nine".