100491091 has 2 divisors, whose sum is σ = 100491092. Its totient is φ = 100491090.

The previous prime is 100491067. The next prime is 100491109. The reversal of 100491091 is 190194001.

Together with next prime (100491109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 100491091 - 2⁵ = 100491059 is a prime.

It is not a weakly prime, because it can be changed into another prime (100491791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50245545 + 50245546.

It is an arithmetic number, because the mean of its divisors is an integer number (50245546).

Almost surely, 2^100491091 is an apocalyptic number.

100491091 is a deficient number, since it is larger than the sum of its proper divisors (1).

100491091 is an equidigital number, since it uses as much as digits as its factorization.

100491091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 100491091 is about 10024.5244775002. The cubic root of 100491091 is about 464.9174571179.

It can be divided in two parts, 1004910 and 91, that added together give a palindrome (1005001).

The spelling of 100491091 in words is "one hundred million, four hundred ninety-one thousand, ninety-one".