217105540 has 12 divisors (see below), whose sum is σ = 455921676. Its totient is φ = 86842208.

The previous prime is 217105531. The next prime is 217105541. The reversal of 217105540 is 45501712.

217105540 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 66846976 + 150258564 = 8176^2 + 12258^2 .

It is not an unprimeable number, because it can be changed into a prime (217105541) 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 in 3 ways as a sum of consecutive naturals, for example, 5427619 + ... + 5427658.

It is an arithmetic number, because the mean of its divisors is an integer number (37993473).

Almost surely, 2^217105540 is an apocalyptic number.

217105540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217105540 is an abundant number, since it is smaller than the sum of its proper divisors (238816136).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

217105540 is a wasteful number, since it uses less digits than its factorization.

217105540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10855286 (or 10855284 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 217105540 is about 14734.5016882146. The cubic root of 217105540 is about 601.0219066713.

The spelling of 217105540 in words is "two hundred seventeen million, one hundred five thousand, five hundred forty".