491489693 has 2 divisors, whose sum is σ = 491489694. Its totient is φ = 491489692.

The previous prime is 491489681. The next prime is 491489707. The reversal of 491489693 is 396984194.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 404291449 + 87198244 = 20107^2 + 9338^2 .

It is a cyclic number.

It is not a de Polignac number, because 491489693 - 2⁶ = 491489629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491489623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245744846 + 245744847.

It is an arithmetic number, because the mean of its divisors is an integer number (245744847).

Almost surely, 2^491489693 is an apocalyptic number.

It is an amenable number.

491489693 is a deficient number, since it is larger than the sum of its proper divisors (1).

491489693 is an equidigital number, since it uses as much as digits as its factorization.

491489693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1679616, while the sum is 53.

The square root of 491489693 is about 22169.5668203057. The cubic root of 491489693 is about 789.1716430771.

The spelling of 491489693 in words is "four hundred ninety-one million, four hundred eighty-nine thousand, six hundred ninety-three".