491611931 has 4 divisors (see below), whose sum is σ = 492088872. Its totient is φ = 491134992.

The previous prime is 491611927. The next prime is 491611949. The reversal of 491611931 is 139116194.

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 491611931 - 2² = 491611927 is a prime.

It is a super-2 number, since 2×491611931² = 483364581403097522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 491611891 and 491611900.

It is not an unprimeable number, because it can be changed into a prime (491611231) 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 3 ways as a sum of consecutive naturals, for example, 236921 + ... + 238986.

It is an arithmetic number, because the mean of its divisors is an integer number (123022218).

Almost surely, 2^491611931 is an apocalyptic number.

491611931 is a deficient number, since it is larger than the sum of its proper divisors (476941).

491611931 is a wasteful number, since it uses less digits than its factorization.

491611931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476940.

The product of its digits is 5832, while the sum is 35.

The square root of 491611931 is about 22172.3235363369. The cubic root of 491611931 is about 789.2370623988.

The spelling of 491611931 in words is "four hundred ninety-one million, six hundred eleven thousand, nine hundred thirty-one".