491738878 has 4 divisors (see below), whose sum is σ = 737608320. Its totient is φ = 245869438.

The previous prime is 491738857. The next prime is 491738879. The reversal of 491738878 is 878837194.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491738879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122934718 + ... + 122934721.

It is an arithmetic number, because the mean of its divisors is an integer number (184402080).

Almost surely, 2^491738878 is an apocalyptic number.

491738878 is a deficient number, since it is larger than the sum of its proper divisors (245869442).

491738878 is a wasteful number, since it uses less digits than its factorization.

491738878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245869441.

The product of its digits is 2709504, while the sum is 55.

The square root of 491738878 is about 22175.1860871561. The cubic root of 491738878 is about 789.3049904048.

The spelling of 491738878 in words is "four hundred ninety-one million, seven hundred thirty-eight thousand, eight hundred seventy-eight".