491909613 has 16 divisors (see below), whose sum is σ = 710040576. Its totient is φ = 301124160.

The previous prime is 491909573. The next prime is 491909641. The reversal of 491909613 is 316909194.

It is not a de Polignac number, because 491909613 - 2²⁶ = 424800749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491909653) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25570 + ... + 40467.

It is an arithmetic number, because the mean of its divisors is an integer number (44377536).

Almost surely, 2^491909613 is an apocalyptic number.

It is an amenable number.

491909613 is a deficient number, since it is larger than the sum of its proper divisors (218130963).

491909613 is a wasteful number, since it uses less digits than its factorization.

491909613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66244.

The product of its (nonzero) digits is 52488, while the sum is 42.

The square root of 491909613 is about 22179.0354389004. The cubic root of 491909613 is about 789.3963304769.

The spelling of 491909613 in words is "four hundred ninety-one million, nine hundred nine thousand, six hundred thirteen".