19678489 has 2 divisors, whose sum is σ = 19678490. Its totient is φ = 19678488.

The previous prime is 19678457. The next prime is 19678507. The reversal of 19678489 is 98487691.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13749264 + 5929225 = 3708^2 + 2435^2 .

It is a cyclic number.

It is not a de Polignac number, because 19678489 - 2⁵ = 19678457 is a prime.

It is not a weakly prime, because it can be changed into another prime (19678429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9839244 + 9839245.

It is an arithmetic number, because the mean of its divisors is an integer number (9839245).

Almost surely, 2^19678489 is an apocalyptic number.

It is an amenable number.

19678489 is a deficient number, since it is larger than the sum of its proper divisors (1).

19678489 is an equidigital number, since it uses as much as digits as its factorization.

19678489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 52.

The square root of 19678489 is about 4436.0442964425. The cubic root of 19678489 is about 269.9793719952.

The spelling of 19678489 in words is "nineteen million, six hundred seventy-eight thousand, four hundred eighty-nine".