491642405 has 4 divisors (see below), whose sum is σ = 589970892. Its totient is φ = 393313920.

The previous prime is 491642401. The next prime is 491642407. The reversal of 491642405 is 504246194.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 131629729 + 360012676 = 11473^2 + 18974^2 .

It is not a de Polignac number, because 491642405 - 2² = 491642401 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491642401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49164236 + ... + 49164245.

It is an arithmetic number, because the mean of its divisors is an integer number (147492723).

Almost surely, 2^491642405 is an apocalyptic number.

It is an amenable number.

491642405 is a deficient number, since it is larger than the sum of its proper divisors (98328487).

491642405 is an equidigital number, since it uses as much as digits as its factorization.

491642405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98328486.

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 491642405 is about 22173.0107337727. The cubic root of 491642405 is about 789.2533697826.

Adding to 491642405 its reverse (504246194), we get a palindrome (995888599).

The spelling of 491642405 in words is "four hundred ninety-one million, six hundred forty-two thousand, four hundred five".