491974513 has 2 divisors, whose sum is σ = 491974514. Its totient is φ = 491974512.

The previous prime is 491974493. The next prime is 491974529. The reversal of 491974513 is 315479194.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 399680064 + 92294449 = 19992^2 + 9607^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-491974513 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 491974513.

It is not a weakly prime, because it can be changed into another prime (491974573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245987256 + 245987257.

It is an arithmetic number, because the mean of its divisors is an integer number (245987257).

Almost surely, 2^491974513 is an apocalyptic number.

It is an amenable number.

491974513 is a deficient number, since it is larger than the sum of its proper divisors (1).

491974513 is an equidigital number, since it uses as much as digits as its factorization.

491974513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 43.

The square root of 491974513 is about 22180.4984840287. The cubic root of 491974513 is about 789.4310452345.

The spelling of 491974513 in words is "four hundred ninety-one million, nine hundred seventy-four thousand, five hundred thirteen".