491638258 has 4 divisors (see below), whose sum is σ = 737457390. Its totient is φ = 245819128.

The previous prime is 491638237. The next prime is 491638267. The reversal of 491638258 is 852836194.

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

It can be written as a sum of positive squares in only one way, i.e., 485453089 + 6185169 = 22033^2 + 2487^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122909563 + ... + 122909566.

Almost surely, 2^491638258 is an apocalyptic number.

491638258 is a deficient number, since it is larger than the sum of its proper divisors (245819132).

491638258 is a wasteful number, since it uses less digits than its factorization.

491638258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245819131.

The product of its digits is 414720, while the sum is 46.

The square root of 491638258 is about 22172.9172189859. The cubic root of 491638258 is about 789.2511506609.

The spelling of 491638258 in words is "four hundred ninety-one million, six hundred thirty-eight thousand, two hundred fifty-eight".