491640402 has 32 divisors (see below), whose sum is σ = 1092916800. Its totient is φ = 146169920.

The previous prime is 491640379. The next prime is 491640403. The reversal of 491640402 is 204046194.

It is a self number, because there is not a number n which added to its sum of digits gives 491640402.

It is not an unprimeable number, because it can be changed into a prime (491640403) 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, 66777 + ... + 73772.

It is an arithmetic number, because the mean of its divisors is an integer number (34153650).

Almost surely, 2^491640402 is an apocalyptic number.

491640402 is an abundant number, since it is smaller than the sum of its proper divisors (601276398).

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

491640402 is a wasteful number, since it uses less digits than its factorization.

491640402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140618.

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 491640402 is about 22172.9655662025. The cubic root of 491640402 is about 789.2522979489.

Adding to 491640402 its reverse (204046194), we get a palindrome (695686596).

The spelling of 491640402 in words is "four hundred ninety-one million, six hundred forty thousand, four hundred two".