491681247949 has 16 divisors (see below), whose sum is σ = 529246608768. Its totient is φ = 455576882112.

The previous prime is 491681247943. The next prime is 491681247971. The reversal of 491681247949 is 949742186194.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 491681247949 - 2⁵ = 491681247917 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 (491681247943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1079442 + ... + 1465795.

It is an arithmetic number, because the mean of its divisors is an integer number (33077913048).

Almost surely, 2^491681247949 is an apocalyptic number.

It is an amenable number.

491681247949 is a deficient number, since it is larger than the sum of its proper divisors (37565360819).

491681247949 is a wasteful number, since it uses less digits than its factorization.

491681247949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2545524.

The product of its digits is 31352832, while the sum is 64.

The spelling of 491681247949 in words is "four hundred ninety-one billion, six hundred eighty-one million, two hundred forty-seven thousand, nine hundred forty-nine".