491011391 has 8 divisors (see below), whose sum is σ = 559886544. Its totient is φ = 426579840.

The previous prime is 491011369. The next prime is 491011447. The reversal of 491011391 is 193110194.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 491011391 - 2⁶ = 491011327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491011891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1110665 + ... + 1111106.

It is an arithmetic number, because the mean of its divisors is an integer number (69985818).

Almost surely, 2^491011391 is an apocalyptic number.

491011391 is a deficient number, since it is larger than the sum of its proper divisors (68875153).

491011391 is a wasteful number, since it uses less digits than its factorization.

491011391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2221801.

The product of its (nonzero) digits is 972, while the sum is 29.

The square root of 491011391 is about 22158.7768389864. The cubic root of 491011391 is about 788.9155611479.

The spelling of 491011391 in words is "four hundred ninety-one million, eleven thousand, three hundred ninety-one".