19691489 has 2 divisors, whose sum is σ = 19691490. Its totient is φ = 19691488.

The previous prime is 19691447. The next prime is 19691513. The reversal of 19691489 is 98419691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19651489 + 40000 = 4433^2 + 200^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19691489 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19691689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9845744 + 9845745.

It is an arithmetic number, because the mean of its divisors is an integer number (9845745).

Almost surely, 2^19691489 is an apocalyptic number.

It is an amenable number.

19691489 is a deficient number, since it is larger than the sum of its proper divisors (1).

19691489 is an equidigital number, since it uses as much as digits as its factorization.

19691489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 47.

The square root of 19691489 is about 4437.5093239339. The cubic root of 19691489 is about 270.0388101504.

The spelling of 19691489 in words is "nineteen million, six hundred ninety-one thousand, four hundred eighty-nine".