491957 has 4 divisors (see below), whose sum is σ = 494700. Its totient is φ = 489216.

The previous prime is 491951. The next prime is 491969. The reversal of 491957 is 759194.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 759194 = 2 ⋅379597.

It can be written as a sum of positive squares in 2 ways, for example, as 303601 + 188356 = 551^2 + 434^2 .

It is a cyclic number.

It is not a de Polignac number, because 491957 - 2¹⁶ = 426421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 491957.

It is not an unprimeable number, because it can be changed into a prime (491951) 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, 1082 + ... + 1467.

It is an arithmetic number, because the mean of its divisors is an integer number (123675).

2⁴⁹¹⁹⁵⁷ is an apocalyptic number.

It is an amenable number.

491957 is a deficient number, since it is larger than the sum of its proper divisors (2743).

491957 is a wasteful number, since it uses less digits than its factorization.

491957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2742.

The product of its digits is 11340, while the sum is 35.

The square root of 491957 is about 701.3964642055. The cubic root of 491957 is about 78.9421677900.

The spelling of 491957 in words is "four hundred ninety-one thousand, nine hundred fifty-seven".