491968140 has 96 divisors (see below), whose sum is σ = 1496893440. Its totient is φ = 120268800.

The previous prime is 491968133. The next prime is 491968153. The reversal of 491968140 is 41869194.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 491968092 and 491968101.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28380 + ... + 42300.

It is an arithmetic number, because the mean of its divisors is an integer number (15592640).

Almost surely, 2^491968140 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 491968140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (748446720).

491968140 is an abundant number, since it is smaller than the sum of its proper divisors (1004925300).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

491968140 is a wasteful number, since it uses less digits than its factorization.

491968140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13983 (or 13981 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 491968140 is about 22180.3548213278. The cubic root of 491968140 is about 789.4276364768.

The spelling of 491968140 in words is "four hundred ninety-one million, nine hundred sixty-eight thousand, one hundred forty".