217461491 has 16 divisors (see below), whose sum is σ = 239458464. Its totient is φ = 196245504.

The previous prime is 217461473. The next prime is 217461521. The reversal of 217461491 is 194164712.

It is not a de Polignac number, because 217461491 - 2¹⁸ = 217199347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217461421) 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 15 ways as a sum of consecutive naturals, for example, 376595 + ... + 377171.

It is an arithmetic number, because the mean of its divisors is an integer number (14966154).

Almost surely, 2^217461491 is an apocalyptic number.

217461491 is a deficient number, since it is larger than the sum of its proper divisors (21996973).

217461491 is a wasteful number, since it uses less digits than its factorization.

217461491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1190.

The product of its digits is 12096, while the sum is 35.

The square root of 217461491 is about 14746.5755685854. The cubic root of 217461491 is about 601.3501917653.

The spelling of 217461491 in words is "two hundred seventeen million, four hundred sixty-one thousand, four hundred ninety-one".