491191507 has 4 divisors (see below), whose sum is σ = 493103016. Its totient is φ = 489280000.

The previous prime is 491191487. The next prime is 491191511. The reversal of 491191507 is 705191194.

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

It is a cyclic number.

It is not a de Polignac number, because 491191507 - 2¹⁵ = 491158739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491191567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 955369 + ... + 955882.

It is an arithmetic number, because the mean of its divisors is an integer number (123275754).

Almost surely, 2^491191507 is an apocalyptic number.

491191507 is a deficient number, since it is larger than the sum of its proper divisors (1911509).

491191507 is a wasteful number, since it uses less digits than its factorization.

491191507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1911508.

The product of its (nonzero) digits is 11340, while the sum is 37.

The square root of 491191507 is about 22162.8406798407. The cubic root of 491191507 is about 789.0120144050.

The spelling of 491191507 in words is "four hundred ninety-one million, one hundred ninety-one thousand, five hundred seven".