491774939 has 4 divisors (see below), whose sum is σ = 498511656. Its totient is φ = 485038224.

The previous prime is 491774909. The next prime is 491774989. The reversal of 491774939 is 939477194.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 939477194 = 2 ⋅469738597.

It is a cyclic number.

It is not a de Polignac number, because 491774939 - 2⁸ = 491774683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491774909) 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, 3368249 + ... + 3368394.

It is an arithmetic number, because the mean of its divisors is an integer number (124627914).

Almost surely, 2^491774939 is an apocalyptic number.

491774939 is a deficient number, since it is larger than the sum of its proper divisors (6736717).

491774939 is an equidigital number, since it uses as much as digits as its factorization.

491774939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6736716.

The product of its digits is 1714608, while the sum is 53.

The square root of 491774939 is about 22175.9991657648. Note that the first 3 decimals coincide. The cubic root of 491774939 is about 789.3242841348.

The spelling of 491774939 in words is "four hundred ninety-one million, seven hundred seventy-four thousand, nine hundred thirty-nine".