491101421 has 2 divisors, whose sum is σ = 491101422. Its totient is φ = 491101420.

The previous prime is 491101393. The next prime is 491101439. The reversal of 491101421 is 124101194.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 462852196 + 28249225 = 21514^2 + 5315^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-491101421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491104421) 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 as a sum of consecutive naturals, namely, 245550710 + 245550711.

It is an arithmetic number, because the mean of its divisors is an integer number (245550711).

Almost surely, 2^491101421 is an apocalyptic number.

It is an amenable number.

491101421 is a deficient number, since it is larger than the sum of its proper divisors (1).

491101421 is an equidigital number, since it uses as much as digits as its factorization.

491101421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 491101421 is about 22160.8082208208. The cubic root of 491101421 is about 788.9637757302.

The spelling of 491101421 in words is "four hundred ninety-one million, one hundred one thousand, four hundred twenty-one".