491997353 has 2 divisors, whose sum is σ = 491997354. Its totient is φ = 491997352.

The previous prime is 491997349. The next prime is 491997409. The reversal of 491997353 is 353799194.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 445716544 + 46280809 = 21112^2 + 6803^2 .

It is a cyclic number.

It is not a de Polignac number, because 491997353 - 2² = 491997349 is a prime.

It is a super-2 number, since 2×491997353² = 484122790718013218, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (491997313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245998676 + 245998677.

It is an arithmetic number, because the mean of its divisors is an integer number (245998677).

Almost surely, 2^491997353 is an apocalyptic number.

It is an amenable number.

491997353 is a deficient number, since it is larger than the sum of its proper divisors (1).

491997353 is an equidigital number, since it uses as much as digits as its factorization.

491997353 is an evil number, because the sum of its binary digits is even.

The product of its digits is 918540, while the sum is 50.

The square root of 491997353 is about 22181.0133447505. The cubic root of 491997353 is about 789.4432615354.

The spelling of 491997353 in words is "four hundred ninety-one million, nine hundred ninety-seven thousand, three hundred fifty-three".