100666591 has 2 divisors, whose sum is σ = 100666592. Its totient is φ = 100666590.

The previous prime is 100666583. The next prime is 100666597. The reversal of 100666591 is 195666001.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 100666591 - 2³ = 100666583 is a prime.

It is a super-2 number, since 2×100666591² = 20267525087122562, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100666597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50333295 + 50333296.

It is an arithmetic number, because the mean of its divisors is an integer number (50333296).

Almost surely, 2^100666591 is an apocalyptic number.

100666591 is a deficient number, since it is larger than the sum of its proper divisors (1).

100666591 is an equidigital number, since it uses as much as digits as its factorization.

100666591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 100666591 is about 10033.2741914093. The cubic root of 100666591 is about 465.1879473020.

The spelling of 100666591 in words is "one hundred million, six hundred sixty-six thousand, five hundred ninety-one".