489971917 has 2 divisors, whose sum is σ = 489971918. Its totient is φ = 489971916.

The previous prime is 489971903. The next prime is 489972031. The reversal of 489971917 is 719179984.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 317338596 + 172633321 = 17814^2 + 13139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-489971917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (489971017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 244985958 + 244985959.

It is an arithmetic number, because the mean of its divisors is an integer number (244985959).

Almost surely, 2^489971917 is an apocalyptic number.

It is an amenable number.

489971917 is a deficient number, since it is larger than the sum of its proper divisors (1).

489971917 is an equidigital number, since it uses as much as digits as its factorization.

489971917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1143072, while the sum is 55.

The square root of 489971917 is about 22135.3092817787. The cubic root of 489971917 is about 788.3584548708.

The spelling of 489971917 in words is "four hundred eighty-nine million, nine hundred seventy-one thousand, nine hundred seventeen".