217145860 has 12 divisors (see below), whose sum is σ = 456006348. Its totient is φ = 86858336.

The previous prime is 217145857. The next prime is 217145869. The reversal of 217145860 is 68541712.

It can be written as a sum of positive squares in 2 ways, for example, as 36942084 + 180203776 = 6078^2 + 13424^2 .

It is not an unprimeable number, because it can be changed into a prime (217145869) 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, 5428627 + ... + 5428666.

It is an arithmetic number, because the mean of its divisors is an integer number (38000529).

Almost surely, 2^217145860 is an apocalyptic number.

217145860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217145860 is an abundant number, since it is smaller than the sum of its proper divisors (238860488).

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

217145860 is a wasteful number, since it uses less digits than its factorization.

217145860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10857302 (or 10857300 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 217145860 is about 14735.8698419876. The cubic root of 217145860 is about 601.0591108551.

The spelling of 217145860 in words is "two hundred seventeen million, one hundred forty-five thousand, eight hundred sixty".