491000781 has 8 divisors (see below), whose sum is σ = 657084544. Its totient is φ = 326125440.

The previous prime is 491000779. The next prime is 491000791. The reversal of 491000781 is 187000194.

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

It is not a de Polignac number, because 491000781 - 2¹ = 491000779 is a prime.

It is a super-2 number, since 2×491000781² = 482163533885219922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491000791) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 301156 + ... + 302781.

It is an arithmetic number, because the mean of its divisors is an integer number (82135568).

Almost surely, 2^491000781 is an apocalyptic number.

It is an amenable number.

491000781 is a deficient number, since it is larger than the sum of its proper divisors (166083763).

491000781 is a wasteful number, since it uses less digits than its factorization.

491000781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 604211.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 491000781 is about 22158.5374291716. The cubic root of 491000781 is about 788.9098786902.

The spelling of 491000781 in words is "four hundred ninety-one million, seven hundred eighty-one", and thus it is an aban number.