19897663 has 2 divisors, whose sum is σ = 19897664. Its totient is φ = 19897662.

The previous prime is 19897627. The next prime is 19897699. The reversal of 19897663 is 36679891.

It is a balanced prime because it is at equal distance from previous prime (19897627) and next prime (19897699).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19897663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19897063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9948831 + 9948832.

It is an arithmetic number, because the mean of its divisors is an integer number (9948832).

Almost surely, 2^19897663 is an apocalyptic number.

19897663 is a deficient number, since it is larger than the sum of its proper divisors (1).

19897663 is an equidigital number, since it uses as much as digits as its factorization.

19897663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 489888, while the sum is 49.

The square root of 19897663 is about 4460.6796567339. The cubic root of 19897663 is about 270.9779941554.

The spelling of 19897663 in words is "nineteen million, eight hundred ninety-seven thousand, six hundred sixty-three".