491231893 has 2 divisors, whose sum is σ = 491231894. Its totient is φ = 491231892.

The previous prime is 491231887. The next prime is 491231933. The reversal of 491231893 is 398132194.

It is an a-pointer prime, because the next prime (491231933) can be obtained adding 491231893 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 310006449 + 181225444 = 17607^2 + 13462^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-491231893 is a prime.

It is a super-3 number, since 3×491231893³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491231863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245615946 + 245615947.

It is an arithmetic number, because the mean of its divisors is an integer number (245615947).

Almost surely, 2^491231893 is an apocalyptic number.

It is an amenable number.

491231893 is a deficient number, since it is larger than the sum of its proper divisors (1).

491231893 is an equidigital number, since it uses as much as digits as its factorization.

491231893 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 40.

The square root of 491231893 is about 22163.7517807794. The cubic root of 491231893 is about 789.0336381271.

The spelling of 491231893 in words is "four hundred ninety-one million, two hundred thirty-one thousand, eight hundred ninety-three".